Non-contact magnetic steering

ABSTRACT

A method of steering a moving metal strip by positioning one or more magnetic rotors near a metal strip. Each rotor includes one or more permanent magnets and rotates to impart a changing magnetic field on the metal strip passing nearby. The magnetic rotors can rotate around an axis of rotation that is parallel to the longitudinal direction of travel of the metal strip. The magnetic rotors can be positioned to impart forces on the strip in any combination of laterally, vertically, or longitudinally. A control mechanism can control the rotor speed, rotor direction, vertical position of the rotors, vertical spacing between rotors, and/or lateral position of the rotors. In some cases, the control mechanism can be coupled to sensors, such as a light curtain and a laser distance sensor, in order to provide closed loop feedback control of a metal strip passing through the non-contact magnetic rotor steering device.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of and priority to U.S. Pat. No.10,738,828 issued on Aug. 11, 2020 and titled “NON-CONTACT MAGNETICSTEERING,” which claims the benefit of and priority to U.S. ProvisionalApplication No. 62/173,097 filed on Jun. 9, 2015 and titled “NON-CONTACTMAGNETIC STEERING,” the contents of both of which are hereinincorporated by reference in their entireties for all purposes.

TECHNICAL FIELD

The present disclosure relates to processing of metal strips generallyand more specifically to steering or controlling of metal strips, inparticular non-ferrous metal strips, during processing.

BACKGROUND

Many metalworking processes involve manipulating and processing ofcontinuous metal strips. Processing metal as strips allows for longlengths of metal to be processed quickly, but requires that the metalstrip remain centered within a certain variance from the desiredpassline of the processing equipment. If the strip wanders too far offthe desired passline of the equipment, the strip may make undesiredcontact with edges of the equipment, the strip may not be processedcorrectly (e.g., not heated or cooled evenly), or other undesirable,dangerous, or costly effects may result. In certain equipment, the metalstrip is being held in high tension, and active steering may not benecessary. However, the need for active steering or control can increasewhen the metal strip is not being held in high tension, such as when thestrip is being first fed into a cold-rolling mill or when processing themetal strip in a continuous annealing line. Active steering can beuseful in other circumstances as well.

Additionally, certain metals, such as aluminum, can be harmed by contactwith equipment. The use of non-contact steering equipment can bedesirable, especially when processing a metal when the metal is soft(e.g., due to heating). Additionally, certain metals can be harmed bylocalized hotspots in the metal.

SUMMARY

The term embodiment and like terms are intended to refer broadly to allof the subject matter of this disclosure and the claims below.Statements containing these terms should be understood not to limit thesubject matter described herein or to limit the meaning or scope of theclaims below. Embodiments of the present disclosure covered herein aredefined by the claims below, not this summary. This summary is ahigh-level overview of various aspects of the disclosure and introducessome of the concepts that are further described in the DetailedDescription section below. This summary is not intended to identify keyor essential features of the claimed subject matter, nor is it intendedto be used in isolation to determine the scope of the claimed subjectmatter. The subject matter should be understood by reference toappropriate portions of the entire specification of this disclosure, anyor all drawings and each claim.

Aspects of the present disclosure include systems and methods formagnetically steering or positioning metal. Systems and methods cansteer moving metal strips or stationary metal pieces through the use ofmagnets that do not physically contact the metal, such as magnetsmounted on a rotor positioned adjacent the metal. In some cases,stationary magnets can be placed adjacent a moving metal strip andelectricity passed through the moving metal strip can induce movement inthe metal strip.

A non-contact steering device can includes one or more magnetic rotorspositioned near a metal strip. Each rotor can include one or morepermanent magnets and can rotate to impart a changing magnetic field onthe metal strip passing nearby. The magnetic rotors can rotate around anaxis of rotation that is parallel to the longitudinal direction oftravel of the metal strip. The magnetic rotors can be positioned toimpart forces on the strip in any combination of laterally, vertically,or longitudinally. A control mechanism can control the rotor speed,rotor direction, vertical position of the rotors, vertical spacingbetween rotors, and/or lateral position of the rotors. In some cases,the control mechanism can be coupled to sensors, such as a light curtainand a laser distance sensor, in order to provide closed loop feedbackcontrol of a metal strip passing through the non-contact magnetic rotorsteering device.

BRIEF DESCRIPTION OF THE DRAWINGS

The specification makes reference to the following appended figures, inwhich use of like reference numerals in different figures is intended toillustrate like or analogous components.

FIG. 1 is a depiction of a magnetic rotor steering device according tocertain aspects of the present disclosure.

FIG. 2 is a front view of the magnetic rotor steering device of FIG. 1according to certain aspects of the present disclosure.

FIG. 3 is a close-up view of a vertical support and two rotors of themagnetic rotor steering device of FIG. 1 according to certain aspects ofthe present disclosure.

FIG. 4 is a close-up rear view of a vertical support and two rotors ofthe magnetic rotor steering device of FIG. 1 according to certainaspects of the present disclosure.

FIG. 5 is a close-up view of a vertical support and two rotors of themagnetic rotor steering device of FIG. 1, with rotor shields in place,according to certain aspects of the present disclosure.

FIG. 6 is a close-up, front, cutaway view of two rotors of a magneticrotor steering device, with coolant shields and rotor shields in place,according to certain aspects of the present disclosure.

FIG. 7 is a top view depicting a permanent-magnet magnetic rotorsteering device in place around a metal strip according to certainaspects of the present disclosure.

FIG. 8 is a front view depicting the permanent-magnet magnetic rotorsteering device of FIG. 7 according to certain aspects of the presentdisclosure.

FIG. 9 is a schematic diagram depicting magnetic rotor steering devicespositioned at various locations in a continuous annealing line accordingto certain aspects of the present disclosure.

FIG. 10 is a schematic side view depicting offset rotors used to inducea sine-wave-type fluctuation in a metal strip according to certainaspects of the present disclosure.

FIG. 11 is a flowchart depicting a feedback control process according tocertain aspects of the present disclosure.

FIG. 12 is a flow chart depicting a process for steering a metal stripwithout feedback control according to certain aspects of the presentdisclosure.

FIG. 13A is an overhead view of a magnetic rotor steering deviceincluding rotors longitudinally positionable above a metal stripaccording to certain aspects of the present disclosure.

FIG. 13B is a front view of the magnetic rotor steering device of FIG.13A including rotors longitudinally positionable above a metal stripaccording to certain aspects of the present disclosure.

FIG. 13C is a side view of the magnetic rotor steering device of FIG.13A including rotors longitudinally positionable above a metal stripaccording to certain aspects of the present disclosure.

FIG. 14 is a schematic, elevation diagram depicting a metal processingsystem including a magnetic rotor steering device used to steer a metalstrip prior to entering strip processing equipment according to certainaspects of the present disclosure.

FIG. 15 is a schematic, top view diagram depicting the metal processingsystem of FIG. 14 according to certain aspects of the presentdisclosure.

FIG. 16 is a schematic, elevation diagram depicting a metal processingsystem including a magnetic rotor steering device used to steer a metalstrip after exiting strip processing equipment according to certainaspects of the present disclosure.

FIG. 17 is a schematic, top view diagram depicting the metal processingsystem of FIG. 16 according to certain aspects of the presentdisclosure.

FIG. 18 is an axonometric depiction of an applied-current magneticsteering apparatus according to certain aspects of the presentdisclosure.

FIG. 19 is a front view of the applied-current magnetic steeringapparatus of FIG. 18 according to certain aspects of the presentdisclosure.

FIG. 20A is a top view of the applied-current magnetic steeringapparatus of FIG. 18 according to certain aspects of the presentdisclosure.

FIG. 20B is a top view of an applied-current magnetic steering apparatusaccording to certain aspects of the present disclosure.

FIG. 21 is a front view of a magnetic rotor steering device according tocertain aspects of the present disclosure.

FIG. 22 is a cutaway side view of a furnace into which a magnetic rotorsteering apparatus can be fit according to certain aspects of thepresent disclosure.

FIG. 23 is a cutaway side view of a furnace that has been modified toreceive a magnetic rotor steering apparatus according to certain aspectsof the present disclosure.

FIG. 24 is a cutaway side view depicting a magnetic rotor steeringapparatus incorporated into a furnace according to certain aspects ofthe present disclosure.

FIG. 25 is a cutaway side view depicting a magnetic rotor steeringapparatus incorporated into a furnace at a furnace entrance according tocertain aspects of the present disclosure.

FIG. 26 is a cutaway side view depicting a magnetic rotor steeringapparatus incorporated into a furnace at a furnace exit according tocertain aspects of the present disclosure.

FIG. 27 is a front view of a magnetic rotor steering device havingsecondary rotors according to certain aspects of the present disclosure.

FIG. 28 is a front view of a magnetic steering device for steering ametal strip according to certain aspects of the present disclosure.

DETAILED DESCRIPTION

Certain aspects and features of the present disclosure relate to anon-contact magnetic rotor steering device and methods for use. Thenon-contact steering device includes one or more magnetic rotorspositioned near a metal strip. Each magnetic rotor includes one or morepermanent magnets (e.g., samarium cobalt, neodymium, or other magnets).As each magnetic rotor rotates, it imparts a changing magnetic field onthe metal strip passing nearby. The magnetic rotors can each rotatearound an axis of rotation that is parallel to the longitudinaldirection of travel of the metal strip. In other aspects, the magneticrotors can rotate around axes of rotation that are perpendicular to thelongitudinal direction of travel of the metal strip. The magnetic rotorscan be positioned to impart forces on the strip in any combination oflaterally, vertically, or longitudinally. A control mechanism cancontrol the rotor speed, rotor direction, vertical position of therotors, lateral position of the rotors, horizontal spacing between therotors, and/or vertical spacing between the rotors. In some cases, thecontrol mechanism is coupled to sensors, such as a light curtain and alaser distance sensor, to provide closed loop feedback control of ametal strip passing through the non-contact magnetic rotor steeringdevice. The steering device can be used on a non-ferrous, conductingmetal strip, such as aluminum. Other conductive, nonferrous metals canbe used.

The steering device can be used whenever adjustments to a metal strip'scurrent passline (e.g., the current path the metal strip is travelingalong through the processing equipment), position, direction, and/orshape are necessary. A steering device can be used to urge a movingmetal strip towards a desired passline. A desired passline can be adesired path along which the metal strip travels through the processingequipment. A passline can include a lateral component (e.g., the lateralposition of the metal strip within the equipment, such as from sidewalls of the equipment) and a vertical component (e.g., the verticalposition of the metal strip within the equipment, such as from top andbottom walls of the equipment). A lateral centerline of a desiredpassline can be known as a centerline target, and can refer to a desiredposition of the lateral centerline of the metal strip when the metalstrip is traveling along the desired passline. A vertical centerline ofa desired passline can be known as a vertical target, and can refer to adesired position of a vertical centerline of the metal strip when themetal strip is traveling along the desired passline.

The steering device can include any number of rotors. Each rotorincludes one or more permanent magnets. Suitable permanent magnets canbe selected based on strength, temperature resistance, and/or otherfactors. Suitable permanent magnets can be selected from any permanentmagnets known today or discovered in the future. Suitable permanentmagnets may include samarium cobalt magnets. Permanent magnets can bearranged around the circumference of the rotor, within the circumferenceof the rotor, or can make up the rotor itself. Permanent magnets can bearranged to alternate direction around the circumference of the rotor.Permanent magnets can be arranged in many different configurations, suchas in a Halbach array to concentrate the magnetic field on the outsideof the rotor.

The rotors are supported proximate the metal strip in any suitable way.One such suitable way includes each rotor located on a rotor arm. Therotor arm can include equipment necessary to drive the rotor. In somecases, a rotor arm includes a driving motor coupled to the rotor througha belt. The driving motor controls the speed and direction of rotationof the rotor itself. The rotor arm can be mounted on a vertical support.In some cases, a single vertical support includes two rotor arms, a toprotor arm positioned above the metal strip or vertical centerline of thedesired passline and a bottom rotor arm positioned below the metal stripor vertical centerline of the desired passline. Any number of rotor armscan be used on a single vertical support. In some cases, the steeringdevice includes two vertical supports, a right vertical supportpositioned proximate the right edge of the strip and a left verticalsupport positioned proximate the left edge of the strip. Any number ofvertical supports can be used on a steering device. Vertical positioningmotors can be used to control the vertical position of one or more rotorarms on a vertical support. Sufficient vertical positioning motors canbe used to provide vertical movement of all rotor arms on a singlevertical support, as well as vertical separation between the rotor armson a single vertical support. Each vertical support is positioned on atrack for horizontal movement (e.g., towards and away from thecenterline of the strip). Horizontal positioning motors can be used tocontrol the horizontal movement of the vertical supports, and thus theattached rotor arms. In some cases, horizontal positioning motors can bepositioned to control horizontal positioning of a single rotor withrespect to its vertical support.

Through the various positioning motors and driving motors, a steeringdevice can provide at least four ranges of motion: rotor speed, rotordirection, vertical positioning of the rotor, and horizontal positioningof the rotor. In some cases, the steering device can additionallyprovide at least a fifth range of motion: vertical gap between anotherrotor sharing the same vertical support. In some cases, a first rotorcan be driven by a rotor motor as an adjacent rotor is driven due tomagnetic coupling with the first rotating rotor.

Any suitable rotor speed can be used. In some cases, a rotor can bestationary (e.g., zero revolutions per minute) until it is needed, atwhich point it is driven at a desired speed. In some cases, a suitablerotational speed for a rotor can be from 0 revolutions per minute (RPM)up to 2000 RPM. In some cases, the speed can exceed 2000 RPM. It may bedesirable to operate rotors with a speed in the ranges of 250-2000 RPM,500-1750 RPM, 1000-1600 RPM, 1200-1500 RPM, 1300-1500 RPM, or any otherranges therein. In some cases, suitable rotational speeds can depend onvarious factors, such as vertical and/or lateral placement of the axesof rotation and strength of the magnets. In some cases, a controllercoupled to a temperature sensor can be used to adjust the rotationalspeed of the rotors to compensate for fluctuations in the strength ofthe permanent magnets of the rotors if the temperature of the magnetsfluctuates. For example, if cooling systems are unable to maintain thetemperature of magnets at a desired level, the strength of the magnetsmay decrease, and a controller can cause the rotor supporting thosemagnets to increase in speed to compensate for the decreased magneticstrength of the magnets.

Each rotor can be encased in a rotor shield. The rotor shield canfurther encase the rotor arm and optionally portions or all of thevertical support. The rotor shield can be one or multiple parts. Therotor shield can be waterproof or can otherwise fluidly isolate therotor from the surrounding environment. The rotor shield can be selectedfrom a magnetically transparent material or a nearly magneticallytransparent material. In other words, the rotor shield may be designedto not absorb any of the magnetic field being produced by the rotatingrotor. The rotor shield can be thermally-insulating. A fluidly-isolatingrotor shield can enable the steering device to be used in or nearcertain equipment where exposure to moisture and fluids may occur, suchas within the quenching sections of a continuous annealing line. Invarious cases, the rotor shield can be any one of or a combination offluid-shielding and/or thermally-insulating.

In some cases, coolant is circulated through or near the rotor to coolthe permanent magnets of the rotor. Coolant can be a fluid, such as acooling gas. In some cases, a heat pipe is incorporated into the rotorarm to extract heat from the rotor. In some cases, coolant is circulatedwithin a space between an inner coolant shield and the rotor shield. Theinner coolant shield can surround the rotor, allowing the rotor to movefreely within the coolant shield. The coolant shield can protect therotor from direct contact with the coolant, while allowing the coolantto flow past and remove heat from the rotor and rotor shield. In caseswhere it is not undesirable to have the rotor come in to direct contactwith the coolant (e.g., if air is the coolant), coolant can becirculated within the volume of a rotor shield, such as with no innercoolant shield being used.

Since permanent magnets can operate at relatively high temperatures(e.g., up to around 550° C. for samarium cobalt magnets, or up to around200° C. for neodymium magnets), only a moderate amount of cooling wouldneed to be implemented if the steering device were to be used within ahigh-temperature zone, such as a furnace. In an example, a non-contactpermanent magnet magnetic rotor steering device used in furnaceoperating at around 600° C. to 650° C. may only require approximately100° C. to 150° C. of cooling. Additional cooling may be desirable toobtain strong magnetic fields from the desired permanent magnets. Someadditional cooling may be required for other parts (e.g., bearings,motors, etc.) used in conjunction with permanent magnets in thenon-contact permanent magnet magnetic rotor steering device. In somecases, samarium cobalt magnets may be desirable over neodymium magnetswhen high heat is expected, as samarium cobalt magnets drop in magneticfield strength slower with higher heats. However, in some cases,neodymium magnets may be desirable over samarium cobalt magnets whenhigher heats are not expected, as neodymium magnets have stronger fieldstrengths at cooler temperatures.

Additionally, the use of permanent magnets requires less energy toinduce steering movements as compared to electromagnets, especially asthe operating temperatures increase. When operating temperaturesincrease too far, electromagnets no longer work properly and significantresources must be spent to sufficiently cool the electromagnets. Bycontrast, permanent magnets work at higher temperatures and require lesscooling.

Moreover, rotating permanent magnets used to steer the metal stripimpart minimal to no heat variations across the width of the strip.Using stationary electromagnets, or inductive steering, to varyinductive fields imparted across the width of the strip to steer thestrip can generate localized hotspots in the strip. Varying inductivefields can be caused by the natural variance in the windings of theelectromagnets. Variances in electromagnet windings can result in somelateral locations generating more heat than in adjacent laterallocations. Localized hotspots can unevenly deform the strip and cancause other manufacturing defects. By contrast, the inductive fieldsgenerated by the rotating permanent magnets do not occur across theentire width of the metal strip and do not occur at a sufficiently highfrequency to induce such localized hotspots. While permanent magnets mayinclude some level of inherent magnetic variance across dimensions orfrom one magnet to another, this variance is averaged out due to therotation of the permanent magnets in the rotor. No single permanentmagnet is being held at any laterally stationary position, and thus anaverage magnetic field is being applied by the rotating permanentmagnets. Thus, the rotating magnetic rotor steering device is able tosteer the metal strip with minimal to no induction of undesirablelocalized hotspots.

In some cases, electromagnets can be used advantageously by beingincluded in a rotor. When placed in a rotor and rotated similarly to howa permanent magnet is rotated, electromagnets can provide changingmagnetic fields without the same concern of localized hotspot formationthat is present when stationary electromagnets are used, as describedabove. Rotating electromagnets in a rotor may include the use ofbrushes, slip rings, or similar electrical rotary joints, instead ofcommutators, to ensure the magnetic field applied to an adjacent metalstrip is continuously changing despite rotation of the electromagnetwithin the rotor. In some cases, the steering device includes at leastfour rotors, with one rotor located at each of the top and bottom sidesof the lateral edges of the strip (e.g., one at the top left, one at thebottom left, one at the top right, and one at the bottom right). Thisfour-rotor configuration enables the steering device to impart lateralforces on the metal strip at or near the edges of the metal strip. Ifthe metal strip begins to laterally wander too far away from the desiredpassline, the rotors near the edge in the direction of the deviation canspin with the proper direction and speed, as well as be positionedhorizontally or vertically, as necessary, to steer or direct the metalstrip back towards the desired passline. Likewise, the rotors on theopposite edge (e.g., away from the deviation) of the metal strip canapply forces to pull the metal strip back towards the desired passline.Additionally, even if the metal strip is running near the desiredpassline, the steering device can still rotate its rotors to imparttension or compression forces across the lateral width of the strip.Such tensile or compressive forces can help keep the metal stripcentered on the desired passline and can help control sheet shape orflatness in the metal strip.

In some cases, pairs of rotors can be positioned longitudinally offset(e.g., further down the continuous length of the strip, rather thanoffset across the width of the strip) from one another in order toimpart a sine-wave-shaped fluctuation in the metal strip. A first pairof rotors can be positioned at or near both edges of the metal strip andvertically offset from and below the metal strip or vertical centerlineof the desired passline. The first pair of rotors can provide upwardssteering to push the metal strip above a normalized passline (e.g., astandard passline without sinusoidal fluctuation). A second pair ofrotors, longitudinally offset from the first pair of rotors, can bepositioned at or near both edges of the metal strip and verticallyoffset from and above the metal strip or vertical centerline of thedesired passline. The second pair of rotors can provide downwardssteering to push the metal strip below the normalized passline.Additional pairs of rotors can be used in longitudinally offsetpositions from the first and second pairs of rotors to induce upwards ordownwards movement of the metal strip. The upwards and downwardsmovement of the metal strip at subsequent longitudinally offsetlocations can induce a sine-wave-shaped fluctuation in the metal strip.This sine-wave-shaped fluctuation can help the metal strip travelthrough the processing equipment without lateral sagging (e.g., withoutthe centerline of the strip sagging more than the edges of the strip)and can correct for shape/flatness conditions, such as crossbow andgullwing. The rotors may be positioned perpendicular or parallel to thelongitudinal axis of the sheet (e.g., the axis that runs in thedirection of sheet travel), or any combination thereof.

The rotors can be cylindrical or generally cylindrical in shape. In somecases, the rotors have a barrel-shaped profile (e.g., the center of therotor has a larger diameter than the edges of the rotor). Thebarrel-shaped profile can be especially useful when inducingsine-wave-shaped fluctuations, as described herein. The barrel-shapedprofile may help to avoid undesired contact between the strip and therotors. Other shaped profiles can be used.

In some cases, at least one rotor is positioned with its axis ofrotation parallel to the lateral width of the metal strip. In oneaspect, a single rotor is positioned above or below the metal strip orvertical centerline of the desired passline to induce upwards ordownwards movement of the metal strip. The single rotor can bepositioned below the strip passline to induce lateral crossbowing of thestrip (e.g., where the center of the strip is vertically offset to ahigher position than the edges of the strip). In some cases, the singlerotor can be located at or near the lateral centerline of a metal strip.Lateral crossbowing can be useful to keep liquids, such as water, frompooling in the center of the strip by allowing them to fall off theedges of the strip. In some cases, a single rotor is positioned with itsaxis of rotation parallel to the longitudinal axis of the metal strip.

The steering device may be especially useful for steering a metal stripthat is not under high tension. For example, the steering device can beused when the metal strip is under longitudinal tension of approximately40 MPa or less, 30 MPa or less, 20 MPa or less, 10 MPa or less, 5 MPa orless, 2 MPa or less, or 1 MPa or less. In some cases, the steeringdevice may be useful for steering a metal strip that is under hightension. For example, the steering device can be useful when the metalstrip is under longitudinal tension of approximately 1 MPa or more, 2MPa or more, 5 MPa or more, 10 MPa or more, 20 MPa or more, 30 MPa ormore, or 40 MPa or more. In some cases, larger diameter rotors (e.g.,larger magnets with stronger magnetic fields) can be useful for steeringmetal strips under higher tensions. In some cases, an increased numberof rotors can be useful for steering metal strips, such as the primaryand secondary rotors described with reference to FIG. 27.

The steering device can induce concerted lateral forces on the strip toinduce lateral movement of the strip, such as to align the strip to adesired passline of the processing equipment or to induce lateral forcesin the metal strip towards a desired passline if the metal stripdeviates too far from the desired passline. The desired passline may beany passline through the equipment, whether or not it follows thecenterline of the equipment. For example, the desired passline may becentered at the vertical and lateral centerline of the equipment;optionally, the desired passline can be offset from either or both ofthe vertical and horizontal centerlines of the equipment. In some cases,the desired passline may be the natural passline of a strip throughequipment (e.g., a path the strip travels through the equipment withoutsteering mechanisms in place). However, optionally, the desired passlinemay be a passline other than the natural passline. The steering devicecan induce opposing lateral forces on the strip to induce lateraltension or compression on the strip. The steering device can inducevertical movement of the strip, such as to raise or lower the stripabove or below its current passline. The steering device can furtherhold the position of the strip at a target vertical position (e.g., withrespect to the top and bottom of a piece of processing equipment) and/ora target lateral position (e.g., with respect to the sidewalls of apiece of processing equipment). For example, the steering device can beused to hold a strip at the desired passline through a piece ofequipment.

A control system can manage the position, speed, and/or direction of therotors of the steering apparatus. The control system can be coupled toone or more sensors for feedback control (e.g., closed-loop feedbackcontrol) of the rotors. The one or more sensors can be positionedadjacent to the rotors of a magnetic rotor steering device or can bespaced a distance apart from the rotors in one or both of an upstream ordownstream direction. Any suitable sensor can be used. In some cases, alateral position sensor, such as a light curtain, is used to detectlateral deviation of the strip from a desired passline. The lateralposition sensor can detect lateral deviation of the strip from center,such as when additional portions of a light curtain are occluded. Thesignal from the lateral position sensor can trigger the control systemto manipulate the rotors to apply additional lateral force to push orpull the strip back towards the desired passline. In some cases, one ormore vertical position sensors (e.g., a laser rangefinder) can be usedto determine if the strip is deviating vertically from a desiredpassline. The vertical position sensor can detect vertical deviation ofthe strip from the desired passline. The signal from the verticalposition sensor can trigger the control system to manipulate the rotors(e.g., move the rotors vertically) to apply additional vertical force topush the strip back towards the desired passline. An array of verticalposition sensors can be used to determine the sheet shape or flatness.The control system can then manipulate the rotors to achieve the desiredshape and/or flatness through application of a suitable force to thestrip.

In some cases, sensors may be coupled to the rotors or rotor motors tomeasure changes in torque while the rotor motors are driving the rotors.The torque measurements can be used to determine information about theposition of the moving metal strip, such as whether the metal strip isrunning higher or lower or is deviating laterally from the desiredpassline.

In some cases, a control system can operate without feedback control,such as without the use of lateral position sensors or vertical positionsensors. In such cases, the control system can run the rotors constantlyduring operation. With properly positioned rotors (e.g., positioned ator just past the lateral edges of the metal strip), constant rotoroperation without feedback can maintain the lateral position of themoving metal strip to a certain extent, which may be suitable forvarious operations. As the metal strip begins to stray laterally fromcenter, the metal strip will move into the moving magnetic fields of oneset of rotors while simultaneously moving away from the moving magneticfields of another set of rotors located at the laterally opposite sideof the metal strip. Since the metal strip is within more of the firstset of moving magnetic fields than in the second set of moving magneticfields, the first set of moving magnetic fields will push the metalstrip towards the desired passline with much stronger force than thesecond set of moving magnetic fields, thus providing an automaticallycorrective action without the need for active feedback from sensors.However, in some cases, active feedback from sensors may be desirablefor more active control.

In some cases, the axis of rotation of a rotor can fall on a verticalplane that is coplanar with an edge of the metal strip, that is within arotor's radius of the edge of the metal strip, or that is distally(e.g., away from the lateral centerline of the desired passline) spacedapart from the edge of the metal strip (e.g., by a distance greater thana rotor's radius). In an example, processing of a metal strip that isone meter in width can include positioning rotors one meter laterallyspaced apart from the lateral centerline of the desired passline,resulting in a 0.5 meter gap between the vertical planes containing theaxes of rotation of the rotors and the edges of the metal strip when themetal strip is traveling along the desired passline.

In an example, a steering device is placed immediately before acold-rolling mill in order to steer the strip as necessary to ensure thestrip is centered as it is fed into the rolling mill. If the stripbegins to deviate from center, the steering device can impart lateralforces to help return the strip to center. Therefore, inaccuracies instrip alignment as the strip is being fed into the steering device canbe corrected, without contacting the metal strip, before the stripfinally enters the rolling mill.

In another example, the steering device is used in or near variousheating equipment, such as induction heaters. Since a heated strip canbe soft, it can be desirable to not contact the metal strip until it hascooled sufficiently or been further processed. The non-contact steeringdevice can ensure the strip remains centered and on an appropriatepassline (e.g., a desired passline) without touching the heated strip.Furthermore, the use of permanent magnets instead of electromagnets canallow the non-contact steering device to operate in or near the hightemperatures of the heating equipment as described herein. Additionally,less cooling is required of permanent magnets as opposed toelectromagnets. The use of permanent magnets instead of electromagnetscan also allow the non-contact steering device to steer the metal stripwith minimal to no induction of localized hotspots therein.

In another example, the steering device is used when wrapping coils.When a metal strip is wrapped into coils, any misalignment of the stripfrom center can result in a faultily-wrapped coil, which may bedifficult to handle, may cause damage to the metal, or may be otherwiseundesirable. To ensure the strip is centered as the coils are beingwrapped, the steering device can be used to keep the strip centeredalong the centerline of the coil.

In another example, the steering device can be used in a no-tension orlow-tension section of a hot mill (e.g., between a reversing section anda tandem section).

In another example, the steering device can be used to stabilizeseparated strands of metal in a low-tension region of a looping pitslitter.

In another example, the steering device can be used to position a movingmetal strip into a correct position within a piece of processingequipment, such as a blanking machine.

In some cases, a magnetic steering apparatus can be referred to as amagnetic positioning apparatus when used to move or position stationarymetal pieces. For example, a magnetic positioning apparatus can includerotating magnets, such as those disclosed herein and with reference tothe various figures, used to generate moving magnetic fields that induceforces in the stationary metal piece to move the stationary metal pieceinto a desired position. One or more rotating magnets can be placedproximate a desired position, such as around a periphery of a stampingmachine, to urge the stationary metal piece into a desired position,such as a desired position within the stamping machine.

In all examples, the non-contact magnetic rotor steering device is ableto control positioning of the metal strip without contacting the metalstrip.

In an example, the non-contact magnetic rotor steering device can beused in a continuous annealing line. In a continuous annealing line,also known as a continuous annealing solution heat treat (CASH) line,metal must pass through numerous sections under low tension. Some CASHlines may be up to approximately 800 meters long or longer. In certainsections, such as the furnace and the cooling sections, the metal stripmay be unsupported by rollers or other contacting devices. The metalstrip may pass through unsupported sections of approximately 100 metersand longer. As future CASH lines are developed, these lengths may becomelonger. In the unsupported sections, the metal strip can be floated oncushions of fluid (e.g., a gas or air). Since the metal strip isunsupported for a substantial distance, the metal strip can tend to varyaway from the desired passline of the processing equipment.Additionally, water quenching nozzles, air nozzles, or other processequipment can push or move the sheet in undesirable ways. If the stripwanders too far from the desired passline, the processing equipment mayneed to be shut down in order to fix the problem. If the strip contactsan edge of the processing equipment, such as an edge of a furnace,damage to the strip, furnace, and surrounding area may ensue, withsignificant losses of time and material. There may also be danger topersonnel if a strip contacts an edge of the processing equipment. Everytime a shutdown occurs, a substantial amount of the metal strip must bescrapped.

In some cases, the use of non-contact magnetic rotor steering devices asdisclosed herein can aid in maintaining a proper position of aslow-moving metal strip in a CASH line or other line where the metalstrip may be unsupported for a duration. Without the use of anon-contact magnetic rotor steering device, a slow-moving metal strip ina CASH line, such as during startup or shutdown of a CASH line, may needto be supported (e.g., by a physically contacting support, such as aroller or piece of wood) until it has reached a minimum speed forsustaining a suitable passline without physically contacting supports. Asuitable passline can be a desired passline or can be a set of passlines(e.g., desired passlines, sub-optimal passlines, or any combinationthereof) that allow a metal strip to pass through the processingequipment without undesired results, such as undesired crashes. However,when a non-contact magnetic rotor steering device is used, the minimumspeed required until the moving metal strip no longer needs to besupported with a physically contacting support may be smaller. Anylength of moving metal strip that is being supported by a physicallycontacting support within a CASH line may need to be scrapped. Thus, theuse of one or more non-contact magnetic rotor steering devices mayreduce the amount of scrap generated, as the moving metal strip wouldneed to be supported by physically contacting supports for a shorterduration of time or for potentially no time, as the minimum speed forsustaining a suitable passline is lower. The ability for the CASH lineto run at a lower minimum speed may provide additional benefits. Forexample, running at a lower minimum speed during startup can generateless scrap as the furnace temperature is increased to its desiredoperating temperature. Because the material passed through the furnacebefore the desired temperature is reached may need to be scrapped, loweravailable strip speeds during startup before the desired furnacetemperature is reached can result in less material passing through thenon-preheated furnace and therefore less material needing to bescrapped.

The non-contact magnetic rotor steering device can be placed in thefurnace section, between the furnace and cooling sections, in thecooling sections, between cooling sections, or after cooling sections ofa CASH line. In addition to providing steering capabilities as describedherein, the non-contact magnetic rotor steering device can operate tofloat the metal strip in locations where air flotation is impractical orundesirable. Multiple steering devices can be used throughout the CASHline. For example, the use of multiple steering devices throughout aCASH line can include any of or any combination of: one or more steeringdevices placed in a furnace section; one or more steering devices placedin a cooling section; one or more steering devices placed immediatelybefore a furnace section; one or more steering devices placed immediateafter a furnace section; one or more steering devices placed immediatelybefore a cooling section; and one or more steering devices placedimmediate after a cooling section.

In another example, a steering device is used to apply lateral forces onthe metal strip. These lateral forces can be used to create the desiredsheet shape and/or flatness as the strip passes through the steeringdevices. Control of sheet shape and/or flatness can be useful on tablerollers and in other equipment. In an example, sheet shape and/orflatness control enables more consistent cooling of the metal strip whenthe metal strip passes through quenching equipment. By helping maintainshape and/or flatness in the metal strip, the steering device can ensurethat cooling fluids dispersed from various nozzles arranged laterallyacross the metal strip reach the metal strip at approximately the sametime. Additionally, improved flatness or introduction of positivecrossbow or a sine wave can keep cooling fluids from pooling in a bowedregion of the metal strip. Furthermore, the steering device can keep thestrip centered within the field of nozzles that disperse the coolingfluid. If the strip does not remain centered, the strip may be cooledunevenly. In some cases where the strip is cooled from the bottom only,such as by water, it may be undesirable to allow the fluid (e.g., water)to reach the top of the strip where it may damage the strip. In suchcases, the coolant nozzles are often equipped with adjustable widthcovers which can block water being sprayed upwards such that the waterdoes not reach the top of the strip. A steering device can be used tokeep the strip centered in the field of nozzles such that the widthcovers do not need to be adjusted. Additionally, strip positionmeasurement in combination with the steering unit can be used to ensurewidth covers are positioned at positions relative to the strip edgesuitable for obtaining desired sheet shape and/or flatness. In somecases, quenching equipment using the steering device disclosed hereincan operate without the need for adjustable width covers. In some cases,given a known input (e.g., width of the metal strip), a steering devicewithout feedback as disclosed herein can operate in conjunction withquenching equipment with adjustable width covers.

The non-contacting magnetic rotor steering device can be relativelysmall in overall dimensions and can be easily incorporated into or nearexisting equipment. For example, the steering device can be attached toa piece of equipment (e.g., a looping pit slitter) to upgrade or improvethat piece of equipment by giving it the ability to automaticallycorrect misalignment as the sheet enters or exits the piece ofequipment.

The steering device can manipulate the strip in many ways, includingtwisting the strip (e.g., by lowering the rotors on one side of thestrip while raising the rotors on the other side of the strip). Not onlycan steering devices be used to maintain control of a strip's positionand/or shape (e.g., correct slight deviations from a desired passline,such as lateral deviations from a lateral centerline of a desiredpassline), but steering devices can be used to actively steer a sheetwithout contacting the sheet (e.g., to turn, rotate, or otherwise guidethe sheet, such as upwards or downwards from one piece of equipment toanother piece of equipment).

In some cases, one or more rotors are supported with additional degreesof freedom (e.g., supported by a robotic arm), allowing the rotors to bepositioned with more precision around the metal strip.

In some cases, a feedback control circuit controls the rotors of thesteering device using a feedback control process. The feedback controlcircuit can be coupled to sensors for measuring one or both of ahorizontal deviation and a vertical deviation of the metal strip. Basedon the measurement(s), the feedback control circuit can determine adirection and strength of correction force necessary to return the metalstrip back to a desired path. In some cases, only the direction of thecorrection force is determined. The direction and strength of correctionforce can be determined for each rotor individually. The feedbackcontrol circuit can then determine, for each rotor, what adjustments arenecessary in order to apply the proper correction force. The determinedadjustments can include adjustments to each rotor's speed, rotor'sdirection, rotor's vertical position, rotor's horizontal position,and/or rotor's vertical separation from another rotor on the samevertical support. In some cases, the determined adjustments includeadjustments based on other degrees of freedom contemplated above. Thefeedback control circuit can then implement the determined adjustmentsby manipulating the rotors as necessary. Manipulating the rotors caninclude adjusting the rotation speed or direction of the permanentmagnet rotors or adjusting the position of the permanent magnet rotorsrelative to the strip. The feedback control process can then repeat asthe feedback control circuit measures one or more of a new horizontaldeviation and a new vertical deviation.

In some cases, a more complicated or less complicated feedback controlcircuit can be used. For example, a feedback control circuit can be setup to simply turn on rotors on one side of the metal strip when thestrip veers too far towards that side. In another example, a feedbackcontrol circuit can use additional sensors, such as full-vision cameras,to determine what adjustments may be necessary in order to return thestrip to a desired path or to keep the strip on a desired path. In somecases, the steering device can be used at both edges of the strip toinduce compressive or tensile stress in the sheet continuously. Thecontinuous stress can achieve desired sheet shape and/or flatness, aswell as hold the strip at the desired position. In other cases, nofeedback loop may be needed. For example, the steering device canoperate continuously (e.g., based on preset settings of rotor speed,direction, and position, without feedback control) to keep the strip onor near its desired passline or otherwise control the strip. In suchcases, additional controls for vertical stability, such as but notlimited to air nozzles, may be optionally included. In some cases, theoperation settings for the steering device without feedback control canbe based on a known or predicted width of the metal strip to beprocessed.

In some cases, a magnetic steering apparatus can include stationarymagnets that, when positioned proximate a moving metal strip, induceforces in the moving metal strip to urge the moving metal strip towardsa desired passline.

These illustrative examples are given to introduce the reader to thegeneral subject matter discussed here and are not intended to limit thescope of the disclosed concepts. The following sections describe variousadditional features and examples with reference to the drawings in whichlike numerals indicate like elements, and directional descriptions areused to describe the illustrative examples but, like the illustrativeexamples, should not be used to limit the present disclosure. Theelements included in the illustrations herein may be drawn not to scale.

FIG. 1 is a depiction of a magnetic rotor steering device 100 accordingto certain aspects of the present disclosure. A metal strip 102 to becontrolled passes through rotors 110 of the steering device 100 in alongitudinal direction 112. The metal strip 102 is shown in partialcut-away for illustrative purposes. Each rotor 110 is made of one ormore permanent magnets arranged to present a magnetic field surroundingits outer surface. As the rotors 110 rotate, changing magnetic fieldsare induced proximate the rotors 110. Through control of the positionand rotation of the rotors 110 of the steering device 100, desirableforces can be induced on the metal strip 102 passing near the rotors110.

The steering device 100 can include two vertical supports 104 movablypositioned on a lateral track 106. In some cases, each vertical support104 is supported by its own lateral track 106. Each vertical support 104can be controlled individually to move along the lateral track 106, thuscontrolling the lateral movement of any rotors 110 coupled to thatparticular vertical support 104. In some cases, the vertical supports104 are controlled jointly to move the same distance in the samedirection (e.g., left or right) or opposite directions (e.g., togetheror apart) along the lateral track 106. Lateral movement of the verticalsupports 104 can be accomplished by one or more linear actuators 124.Lateral movement of the vertical supports 104 can allow the steeringdevice 100 to accommodate metal strips 102 of various widths, as well asallow for further control of the changing magnetic fields imparted bythe rotors 110.

Each vertical support 104 can include one or more rotor arms 108. Insome examples, such as that shown in FIG. 1, each vertical support 104includes two rotor arms 108 such that one can be positioned below thestrip 102 while the other is positioned above the strip 102. Each rotorarm 108 can be covered by a protective rotor shield 120, as described infurther detail herein. As seen in FIG. 1, for illustrative purposes, therotor arms 108 on the leftmost vertical support 104 are shown withouttheir rotor shields 120, while the rotor arms 108 of the rightmostvertical support 104 are hidden from view by their rotor shields 120.Each rotor arm 108 supports one or more rotors 110. The verticalposition of each rotor arm 108 on a vertical support 104 can becontrolled individually, thus controlling the vertical movement of anyrotor 110 coupled to that particular rotor arm 108. In some cases, therotor arms 108 of a single vertical support 104 can be controlledjointly to move the same distance in the same direction (e.g., up ordown) or opposite directions (e.g., together or apart) along thevertical support 104. Vertical control can be accomplished by one ormore linear actuators 122.

Each rotor arm 108 can include one or more rotors 110. The rotor arm canhouse a rotor motor 116 for all or each rotor 110 on the rotor arm 108.The rotor motor 116 can be protected by magnetic shielding 126. Forillustrative purposes, the magnetic shielding 126 surrounding the topleft rotor motor 116 is hidden in FIG. 3. The rotor motor 116 can becoupled to a rotor 110 using a transfer belt 114 to control rotation ofthe rotor 110. The transfer belt 114 can be any suitable device fortransferring rotation to the rotor 110, such as a chain or flat belt. Insome cases, the rotor motor 116 can be located elsewhere. The rotormotor 116 may provide power to rotate any attached rotor 110 in aninward direction 118 (e.g., the side of the rotor closest the metalstrip 102 moves towards the center of the metal strip 102) or an outwarddirection (e.g., rotation opposite the inward direction 118). The terms“inward direction” and “outward direction” are used herein forconvenience to help describe the general direction of rotation of therotors with reference to a sheet passing near the rotor. It should beapparent that when a first rotor 110 positioned above a metal strip 102on a vertical support 104 is rotating in an inward direction (e.g.,rotating counter-clockwise when viewed facing the steering device 100 inthe longitudinal direction 112 of metal strip movement as depicted inFIG. 1), it will actually be rotating in an opposite direction from asecond rotor 110 positioned below the metal strip 102 on the samevertical support 104 that is also spinning in an inward direction (e.g.,the inwardly rotating rotor 110 below the metal strip 102 would berotating clockwise when viewed facing the steering device 100 in thelongitudinal direction 112 of metal strip movement as depicted in FIG.1).

The direction and speed of rotation of each rotor 110 can beindividually controlled. In some cases, rotors 110 on a single verticalsupport 104 are jointly controlled to rotate at the same speed and/or inthe same direction relative to the strip 102.

In some cases, each rotor arm 108 and/or rotor 110 is individuallycontrolled to adjust the lateral distance of the rotor 110 from thevertical support 104. In some cases, a rotor arm 108 may be anchored tothe vertical support 104 to pivot with respect to the vertical support104 (e.g., pivoting about an axis of rotation that is perpendicular tothe vertical support 104).

As shown in FIG. 1, the rotors 110 are positioned adjacent the edges ofthe strip 102 and oriented such that each rotor's 110 axis of rotation128 is parallel to the longitudinal direction 112 of the strip 102. Inother configurations, the axis of rotation 128 of each rotor 110 can benon-parallel to the longitudinal direction 112 of the strip 102.Furthermore, each rotor's 110 axis of rotation 128 can be adjustablewith reference to the strip 102, such as by rotation of its verticalsupport 104 along a vertical axis of rotation extending from the bottomof the vertical support 104 through its top. In some configurations, therotors 110 can be positioned above or below the metal strip 102 (e.g.,not directly adjacent an edge); can be positioned directly above orbelow an edge of the metal strip 102; or can be near an edge of themetal strip 102, without being directly above or below the metal stripor the edge of the metal strip. When the steering device 100 includes atleast two rotors 110 positioned laterally opposite one another acrossthe center of the metal strip, the distance between the axis of rotation128 of the two rotors 110 can be less than, equal to, or greater thanthe width of the metal strip 102.

The steering device 100 can include shielding (not shown), as describedin further detail herein. The use of shielding can be desirable toprotect equipment from damage from an errant metal strip, to controltemperature of components within the shielding, or for other purposes.In some cases, rotors 110 can be used without any shielding (e.g.,without rotor shields 120).

FIG. 2 is a front view of the magnetic rotor steering device 100 of FIG.1 according to certain aspects of the present disclosure. Forillustrative purposes, the rotor shields 120 are not shown in FIG. 2.The steering device 100 includes two vertical supports 104 on respectivelateral tracks 106. Each vertical support 104 carries two rotor arms108, which each carries a rotor 110. The four rotors 110 can becontrollably positionable around the metal strip 102 as describedherein. As seen in FIG. 2, all of the rotors 110 are spinning in aninward direction (e.g., the top right and bottom left rotors 110 arerotating in a clockwise direction as seen in FIG. 2 while the top leftand bottom right rotors 110 rotate in a counter-clockwise direction).Such inward rotation of all rotors 110 can result in compressive forcesbeing applied laterally across the metal strip 102. The rotors 110 canrotate in directions opposite to those shown in FIG. 2 to apply tensileforces laterally across the metal strip 102.

The position of rotors 110 can be described with reference to eachrotor's 110 axis of rotation 128 or with reference to planes on whichthe axes of rotation lie. A rotor plane 202 can be defined by the axisof rotation of one or more rotors 110 on one side of a lateralcenterline 208 of the metal strip 102 or of a lateral centerline 214 ofa desired passline. The rotor plane 202 can extend vertically from theaxis of rotation. As seen in FIG. 2, the rotor plane 202 is laterallyspaced apart from the edge 212 of the metal strip 102 (e.g., a verticalline 204 coplanar with an edge 212 of the metal strip 102) by a distance206. In some cases, the rotor plane 202 can be vertically aligned withthe edge 212 of the metal strip 102 (e.g., distance 206 is zero orapproximately zero). In some cases, the rotor plane 202 can be laterallyspaced apart from the edge 212 of the metal strip 102 away from acenterline 208 of the metal strip 102 (e.g., the distance between thecenterline 208 of the metal strip and the rotor plane 202 is greaterthan half the width of the metal strip 102). In some cases, the rotorplane 202 can be laterally spaced apart from the edge 212 of the metalstrip 102 between the centerline 208 of the metal strip 102 and the edge212 of the metal strip 102 (e.g., the distance between the centerline208 of the metal strip 102 and the rotor plane 202 is less than half thewidth of the metal strip 102).

In some cases, rotor placement can be described based on the distancebetween the rotor planes 202, assuming the rotor planes 202 are centeredaround the lateral centerline 208 of the metal strip 102 or a lateralcenterline 214 of a desired passline. For rotors placed at the edges ofthe metal strip 102, the rotor planes 202 can be separated by a distancethat is approximately equal to the width of the metal strip 102, such aswithin a deviation at or less than 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%,or 1%. For rotors placed within the edges or outside of the edges of themetal strip 102, the rotor planes 202 can be separated by a distancethat is less than or greater than, respectively, the width of the metalstrip 102. In some cases, the distance can be greater than the width ofthe metal strip 102 by at least a sum of the radii of opposing rotors ineach of the rotor planes 202, such that the rotors are not directly overthe metal strip 102 when the metal strip 102 is centered on the desiredpassline. In some cases, the distance can be greater than the width ofthe metal strip 102 by at least 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%,or 100% or more of the width of the metal strip 102.

In cases where the distance between the rotor planes 202 is greater thanthe width of the metal strip, the rotor planes 202 can each bepositioned between an edge 212 of the metal strip 102 and anobstruction, such as a wall of the equipment, an adjacent piece ofequipment, a wall of a building, an operator walkway, or other suchobstacles that may be in danger of contacting the moving metal strip 102if the metal strip 102 deviates too far from the desired passline. Therotor planes 202 can be positioned anywhere between the obstruction andthe metal strip 102 to ensure the metal strip 102 is steered towards thedesired passline before contacting the obstruction.

Additionally, the axis of rotation of each rotor 110 intersects a commonlongitudinal plane 210. As depicted in FIG. 2, the common longitudinalplane 210 is a plane that is coplanar with the page of FIG. 2 andintersects each of the rotors 110 of the magnetic rotor steering device100.

FIG. 3 is a close-up view of a vertical support 104 and two rotors 110of the magnetic rotor steering device 100 of FIG. 1 according to certainaspects of the present disclosure. For illustrative purposes, the rotorshields 120 and metal strip 102 are not shown in FIG. 3. The verticalsupport 104 is shown supporting two rotor arms 108, each of whichsupports a rotor 110. Each rotor arm 108 includes a rotor motor 116coupled to a respective rotor 110 by a respective transfer belt 114. Thelinear actuator 124 for laterally moving the vertical support 104 alongthe lateral track 106 can be seen. In some cases, the rotor motor 116includes magnetic shielding 126 capable of attenuating the changingmagnetic fields created by the spinning rotor 110. In such cases, amagnetic-based motor (e.g., as opposed to a pneumatic- orhydraulic-based motor) can be used. For illustrative purposes, themagnetic shielding 126 of the top rotor motor 116 is not shown in FIG.3. A segment of the common longitudinal plane 210 is depicted in FIG. 3.

FIG. 4 is a close-up rear view of a vertical support 104 and two rotors110 of the magnetic rotor steering device 100 of FIG. 1 according tocertain aspects of the present disclosure. For illustrative purposes,the top rotor shield 120 and the metal strip 102 are not shown in FIG.4, however the bottom rotor shield 120 is shown with slits 121. Thevertical support 104 is shown supporting two rotor arms 108, each ofwhich supports a rotor 110. A linear actuator 402 controls the verticalmovement of each rotor arm 108 along the vertical support 104. Othermechanisms can be used to control vertical movement of each rotor arm108, including any suitable linear actuator such as those describedherein. In some cases, linear actuators 402 are powered by motors 404.

Linear actuator 124 for controlling lateral movement of the verticalsupport 104 along the lateral track 106 can be seen. In some cases,linear actuator 124 can be powered by a motor 406.

FIG. 5 is a close-up view of a vertical support 104 and two rotors 110of the magnetic rotor steering device 100 of FIG. 1, with rotor shields120 in place, according to certain aspects of the present disclosure.The metal strip 102 passes between the rotor shields 120 so that thechanging magnetic field induced by rotation of the rotors 110 within therotor shields 120 passes through the metal strip 102. The verticalsupport 104 is shown supporting two rotor arms 108, each of whichsupports a rotor 110, and each of which is encapsulated by a rotorshield 120.

As described in further detail herein, the rotor shield 120 can besingle-layered or multi-layered and can protect the rotor 110 and otherequipment within the rotor shield 120 from dust, debris, fluid, or othercontaminants. The rotor shield 120 can also be thermally-insulating,thus decreasing the amount of heat transferred across the rotor shield120.

The rotor shield 120 can be of any suitable profile or shape. In somecases, additional shielding is included on or around the verticalsupport 104. The additional shielding can be coupled to or continuouswith the rotor shields 120 of the vertical support 104. The additionalshielding can help protect and cool any motors and actuators associatedwith the rotor 110 or vertical support 104.

In some cases, such as when a rotor shield 120 is made from a metal, therotor shield 120 can include slits 121 or other openings for reducingeddy currents in the rotor shield 120. Without such slits 121 or otheropenings, the moving magnetic fields created by the rotor 110 may inducesubstantial heat buildup in electrically conductive rotor shields 120.The slits 121 or other openings can be any suitable shape or pattern forreducing eddy currents. In some cases, the slits 121 or other openingsare subsequently filled with or covered with an electrically insulatingmaterial. In some cases, the rotor shield 120 includes an outer layer orcovering of a non-conductive material, such as Polytetrafluoroethylene(PTFE). In some cases, the rotor shield 120 is made from anon-electrically conducting material and does not include slits 121 orother openings. In some cases, lamination is used to reduce the effectof eddy currents.

In some cases, a rotor shield 120 is made from a metal, such asstainless steel, to protect the rotor 110 in the event of contact by amoving metal strip. In some cases, a rotor shield 120 includes a layerof PTFE (e.g., Teflon™) or other low-friction coating to reduce damageto the metal strip or rotor shield 120 in the event the moving metalstrip contacts the rotor shield 120.

An optional displacement sensor 502 is additionally shown in FIG. 5. Thedisplacement sensor 502 can be coupled to a vertical support 104, rotorarm 108, rotor shield 120, or any other suitable equipment. Thedisplacement sensor 502 can be coupled to remain laterally stationarywith respect to a rotor 110. The displacement sensor 502 can be coupledto remain vertically stationary with respect to a rotor arm 108. In somecases, the displacement sensor 502 can measure vertical displacement ofthe metal strip 102 with respect to a rotor 110. In some cases, thedisplacement sensor 502 can measure lateral displacement of the metalstrip 102 with respect to a rotor 110.

In an example, the displacement sensor 502 is a laser sensor providing afirst beam 504 and a second beam 506. The first beam 504 can be alignedwith a desired edge location of the metal strip 102, whereas the secondbeam 506 can be laterally spaced apart from the desired edge location ofthe metal strip 102 (e.g., towards a desired passline, as depicted inFIG. 5, or away from a desired passline). Each beam 504, 506 can measurethe presence of the metal strip 102 underneath or measure a distancefrom the displacement sensor 502 to the metal strip 102. Thesemeasurements can be used to approximate or otherwise determine thelocation of the edge of the metal strip 102 with respect to the rotors110. The displacement sensor 502 can be used as a feedback sensor toprovide of the location of the metal strip 102 as described in furtherdetail herein.

FIG. 6 is a close-up, front, cutaway view of two rotors 610 of amagnetic rotor steering device 600, with coolant shields 602 and rotorshields 612 in place, according to certain aspects of the presentdisclosure. Each rotor arm 614 can support a rotor 610. A shieldsurrounding the rotor 610 and rotor arm 614 can include a rotor shield612 (e.g., an outer layer) and a coolant shield 602 (e.g., an innerlayer). The rotor shield 612 and coolant shield 602 can act together toform a protective shield 608 around the rotor 610 and any othersurrounded parts. In some cases, coolant 604 can be circulated throughspace between the coolant shield 602 and rotor shield 612. In somecases, coolant 604 is circulated through pathways or tubes locatedbetween the coolant shield 602 and rotor shield 612. Coolant 604 can becirculated using a coolant pump 606.

In an example, the coolant pump 606 pumps coolant 604 into the spacebetween the coolant shield 602 and rotor shield 612 at a side of theprotective shield 608 closest the metal strip 616. Coolant 604 cancirculate within the protective shield 608 and be pulled out at sides ofthe protective shield 608 furthest from the metal strip 102. However,coolant 604 can be circulated in other fashions. Coolant 604 circulatedthrough the protective shields 608 can extract heat from the rotor 610and release the extracted heat (e.g., be cooled) before being pumpedthrough the protective shields again 608. Other parts (e.g., bearings,motors, actuators) can be cooled in the same manner.

In some cases, a coolant pump pumps coolant into the entire volume ofthe coolant shield 602 or rotor shield 612 (e.g., if no separate coolantshield 602 is used). The coolant can be circulated around the partswithin the coolant shield 602 or rotor shield 612. Movement of the rotor610 can assist in moving the coolant throughout the entire volume of thecoolant shield 602 or rotor shield 612. In some cases, ducting or otherfeatures can be used to direct the flow of coolant near or past therotors 610.

Coolant 604 can be any suitable coolant, including fluids such as air,water, or refrigerants.

FIG. 7 is a top view depicting a permanent-magnet magnetic rotorsteering device 700 in place around a metal strip 702 according tocertain aspects of the present disclosure. A metal strip 702 to becontrolled passes through rotors 710 of the steering device 700 in alongitudinal direction 712. Each rotor 710 is made of one or morepermanent magnets 752 arranged to present a magnetic field surroundingits outer surface. As the rotors 710 rotate, changing magnetic fieldsare induced proximate the rotors 710. Through control of the positionand rotation of the rotors 710 of the steering device 700, desirableforces can be induced on the metal strip 702 passing near the rotors710. Each rotor 710 can rotate about its own axis of rotation 770. Eachrotor 710 can intersect a common plane 772 that is perpendicular to thelongitudinal direction 712 (e.g., direction of travel) of the metalstrip 702. The axes of rotation 770 of each rotor 710 can be parallelthe longitudinal direction 712 or not parallel the longitudinaldirection 712. The metal strip 702 can pass through the common plane772. Regardless of the orientation of the axes of rotation 770 of eachrotor 710 with respect to the longitudinal direction 712, the rotors 710can be spaced apart from one another at the common plane 772.

The steering device 700 can include two vertical supports 704 movablypositioned on a lateral track 706. Each vertical support 704 can becontrolled individually to move along the lateral track 706, thuscontrolling the lateral movement of any rotors 710 coupled to thatparticular vertical support 704. In some cases, the vertical supports704 are controlled jointly to move the same distance in the samedirection (e.g., left or right) or opposite directions (e.g., togetheror apart) along the lateral track 706. Lateral movement of the verticalsupports 704 can be controlled by motor 754. Motor 754 can drive alinear screw 756 that moves the vertical supports 704 along the lateraltrack 706.

Each vertical support 704 can include one or more rotor arms 708. Eachrotor arm 708 supports one or more rotors 710. The vertical position ofeach rotor arm 708 on a vertical support 704 can be controlledindividually, thus controlling the vertical movement of any rotors 710coupled to that particular rotor arm 708. Positioning motors 760 cancontrol the vertical movement of respective rotor arms 708. In somecases, a sufficient number of positioning motors 760 are used toindividually control vertical movement of each rotor arm 708 (e.g., onepositioning motor 760 per rotor arm 708). In some cases, a singlepositioning motor 760 can jointly control the vertical movement of allrotor arms 708 on a particular vertical support 704.

Each rotor arm 708 and associated rotor 710 can be enclosed in aprotective shield 750, as described in further detail herein.

In some cases, a light curtain sensor (e.g., a light curtain transmitter762 and a light curtain receiver 764) can be positioned near the rotors710 in order to detect lateral displacement of the metal strip 702.Lateral displacement can be detected based on displacement away from alateral centerline 768 of a desired passline. If the metal strip 702begins deviating too far laterally in one direction or another, acontroller can alter the position, rotation speed, and/or rotationdirection of one or more rotors 710 in order to impart forces on themetal strip 702 to correct the deviation.

In some cases, one or more vertical position sensors 766 are positionednear the rotors 710 to measure vertical deviation of the metal strip 702from a desired passline. If the metal strip 702 begins deviating too farvertically in one direction or another, a controller can alter theposition, rotation speed, and/or rotation direction of one or morerotors 710 in order to impart forces on the metal strip 702 to correctthe deviation.

The one or more vertical position sensors 766 can also be used to makeinitial measurements (e.g., an initial passline elevation measurement)prior to moving the rotors 710 into an operating position (e.g.,adjacent the metal strip 702). The rotors 710 can be held at anon-operating position (e.g., distant from a desired or expectedpassline of the metal strip 702) until an initial passline elevationmeasurement is taken, after which time each rotor 710 can be moved to anoperating position.

Rotor motors 758 can be located on each rotor arm 708 to power therotational movement of the rotor 710. Rotor motors 758 are shown asbeing located external to the rotor arm 708 and the protective shield750, however in some cases, the rotor motors 758 are located within therotor arm 708 and/or the protective shield 750.

FIG. 8 is a front view depicting the permanent-magnet magnetic rotorsteering device 700 of FIG. 7 according to certain aspects of thepresent disclosure. The metal strip 702 is seen between the rotors 710.As seen in FIG. 8, each rotor 710 includes several permanent magnets 752coupled to an external surface. Adjacent permanent magnets 752 on asingle rotor 710 can be arranged to present a different magnetic pole(e.g., alternating north and south poles facing radially outward).Optionally, adjacent permanent magnets 752 on a single rotor 710 can bearranged according to other configurations, such as but not limited to aHalbach array configuration or other configuration. Permanent magnets752 of a rotor 710 can be coupled to an exterior surface of the rotor710 or encapsulated in a casing of the rotor 710. While a singleconfiguration of magnets is depicted in FIGS. 7-8, other configurationsof magnets can be used with respect to a rotor 710. For example, severalpermanent magnets can be arranged across the width of the rotor (e.g.,in the space occupied by permanent magnet 752 depicted in FIG. 7) and/orthe circumference of the rotor in any suitable arrangement, such as aHalbach array, designed to output a desired magnetic field surroundingthe rotor 710 when the rotor 710 rotates. In one example, each of thepermanent magnets 752 depicted in FIGS. 7-8 can instead be replaced by aHalbach array of several magnets coupled together in the shape ofpermanent magnet 752.

Vertical supports 704 are shown and are each movably positionable alongthe lateral track 706 through actuation of respective motors 754.

Rotor arms 708 are shown supporting respective rotors 710 and enclosedin respective protective shields 750. Vertical positioning of the rotors710 of a vertical support 704 individually and jointly can beaccomplished through positioning motors 760, respectively.

Rotor motors 758 can be located on each rotor arm 708 to power therotational movement of the rotor 710. Rotor motors 758 are shown asbeing located external to the rotor arm 708 and the protective shield750, however in some cases, the rotor motors 758 are located within therotor arm 708 and/or the protective shield 750.

A light curtain sensor (e.g., a light curtain transmitter 762 and alight curtain receiver 764) is shown adjacent rotors 710. Light 806emitted from the light curtain transmitter 762 is received by the lightcurtain receiver 764. By tracking where the emitted light 806 does anddoes not reach the light curtain receiver 764, the light curtain sensorcan detect the lateral displacement of the metal strip 702.

Vertical position sensors 766 are shown adjacent rotors 710. In somecases, laser light 804 is bounced off the surface of the metal strip 702by the vertical position sensors 766 to measure vertical deviation ofthe metal strip 702 from a vertical centerline 802 of a desiredpassline. The thickness of the metal strip can be known or calculated toaccount for the distance between the surface of the metal strip and thecenter of the metal strip. If the metal strip 702 begins deviating toofar vertically in one direction or another, a controller can alter theposition, rotation speed, and/or rotation direction of one or morerotors 710 in order to impart forces on the metal strip 702 to correctthe deviation.

FIG. 9 is a schematic diagram depicting magnetic rotor steering devices902 positioned at various locations in a continuous annealing line 900according to certain aspects of the present disclosure. A portion of acontinuous annealing line 900 is shown, including a furnace section 908and a cooling section 910 separated by a gap 912. A metal strip 904 canpass through the continuous annealing line 900 in direction 906.

The furnace section 908 can include a first furnace zone 914 and asecond furnace zone 916 separated by a gap 918. The cooling section 910can include a first cooling zone 920 and a second cooling zone 922separated by a gap 924. As shown, an optional thermal booster zone 926is located between the furnace section 908 and the cooling section 910.A gap 928 is located between the furnace section 908 and the thermalbooster zone 926 and a gap 930 is located between the thermal boosterzone 926 and the cooling section 910. In the thermal booster zone 926,the temperature of the metal strip 904 can be maintained, rather thanheated or cooled. In some cases, no thermal booster zone 926 is used,and the gap 912 is relatively small, with the furnace section 908 endingadjacent to the beginning of the cooling section 910. In some cases, thethermal booster zone 926 is simply one of the cooling zones of thecooling section 910 operated in a thermal booster mode.

In some cases, the furnace section 908, cooling section 910, and/orthermal booster zone 926 can have fewer or more zones than shown in FIG.9. Each zone of a particular section (e.g., the first furnace zone 914and second furnace zone 916 of the furnace section 908) can include itsown housing (e.g., the first furnace zone 914 is in a separate housingfrom the second furnace zone 916). A steering device 902 placed within azone can be placed within the housing for that particular zone, whereasa steering device 902 placed in a gap (e.g., gap 918) may be placedoutside the housing of either surrounding zone. In some cases, one ormore zones of a particular section (e.g., the first furnace zone 914 andthe second furnace zone 916 of the furnace section 908) or even ofadjacent sections (e.g., the second furnace zone 916 and the thermalbooster zone 926 or first cooling zone 920), are located in a shared,common housing (e.g., the first furnace zone 914 and the second furnacezone 916 are located in a single furnace housing). In such cases, asteering device 902 placed within a zone can be located in the samecommon housing as, but at a different location than, a steering device902 placed in a gap (e.g., gap 918). For example, a steering device 902placed within a first furnace zone 914 can be located within the sameoverall housing as a steering device 902 placed in gap 918, however thesteering device 902 placed within the first furnace zone 914 may beadjacent temperature control elements of the first furnace zone 914. Asingle continuous annealing line 900 can include one or many housings,with one or more sections (e.g., furnace section 908 and cooling section910) and/or zones (e.g., first furnace zone 914 and thermal booster zone926) having individual or shared housings. In other words, the term“gap,” as used below, reflects a general space between adjacentelements, but may or may not reflect a space between the physicalhousings of adjacent elements.

While shown with eleven steering devices 902 (e.g., such as steeringdevice 100 from FIG. 1 or steering device 700 from FIG. 7) in FIG. 9, acontinuous annealing line 900 can have fewer or more steering devices902, in any combination of locations. A steering device 902 can belocated prior to the furnace section 908 (e.g., adjacent the entrance ofthe furnace section 908). A steering device 902 can be located withinthe furnace section 908, such as within the first furnace zone 914,within the gap 918, and/or within the second furnace zone 916. Asteering device 902 can be located in the gap 912 between the furnacesection 908 and the cooling section 910. When a thermal booster zone 926is used, a steering device 902 can be located within the gap 928, withinthe thermal booster zone 926, and/or within the gap 930. A steeringdevice 902 can be located within the cooling section 910, such as withinthe first cooling zone 920 (e.g., within and adjacent the entrance tothe first cooling zone 920), within the gap 924, and/or within thesecond cooling zone 922. A steering device 902 can be located after thecooling section 910 (e.g., adjacent the exit of the cooling section910). A steering device 902 can be located in other locations in acontinuous annealing line 900.

FIG. 10 is a schematic side view depicting offset rotors 1010 used toinduce a sine-wave-type fluctuation in a metal strip 1002 according tocertain aspects of the present disclosure. The strip 1002 is showntravelling in direction 1012. Three rotors 1010 are shown inlongitudinally offset positions. Rotors 1010 can be aligned such thateach rotor's axis of rotation is parallel the longitudinal direction ofthe strip, as shown. In some cases, rotors 1010 can be aligned such thateach rotor's axis of rotation is parallel the lateral width of the strip(not shown).

Each rotor 1010 can impart forces on the metal strip 1002 to verticallydisplace the metal strip 1002 from a vertical path 1004 of a neutralpassline (e.g., a generally flat passline or an expected passline). Whenadjacent rotors 1010 are longitudinally offset and alternatinglypositioned on opposite sides of the metal strip 1002 (e.g., alternatingbetween above the passline and below the passline), the verticaldisplacements from the rotors 1010 cause a sine-wave-type fluctuation inthe metal strip 1002, as seen in FIG. 10. In some cases, the rotors 1010can have profiles that match the general sine-wave-type shape of themetal strip 1002, allowing the rotors 1010 to be positioned near themetal strip 1002 without danger of contacting the metal strip 1002. Forexample, the rotors 1010 can be barrel-shaped, although other shapedprofiles can be used.

FIG. 11 is a flowchart depicting a feedback control process 1100according to certain aspects of the present disclosure. The feedbackcontrol process 1100 can be performed by a controller (e.g., one or moreapplication specific integrated circuits (ASICs), digital signalprocessors (DSPs), digital signal processing devices (DSPDs),programmable logic devices (PLDs), field programmable gate arrays(FPGAs), processors, micro-controllers, microprocessors, otherelectronic units designed to perform the functions described herein,and/or a combination thereof) coupled to any combination of the sensors,positioning motors, and driving motors disclosed herein.

At block 1102, a horizontal deviation can be sensed, such as by a lightcurtain. Sensing the horizontal deviation can include measuring theamount of horizontal deviation. At block 1104, a vertical deviation canbe sensed, such as by a vertical position sensor. Sensing the verticaldeviation can include measuring the amount of vertical deviation. Incertain feedback control processes 1100, either or both of block 1102and block 1104 can be performed.

At block 1106, a direction of correction force can be determined basedon the horizontal deviation measurement and/or vertical deviationmeasurement from respective blocks 1102 and 1104. At block 1108, astrength of correction force can be determined based on the horizontaldeviation measurement and/or vertical deviation measurement fromrespective blocks 1102 and 1104.

At block 1110, the adjustments to the permanent magnet rotors can bedetermined. The determined adjustments can be based on the direction ofcorrection force determined at block 1106 and/or the strength ofcorrection force determined at block 1108.

At block 1112, the rotors are manipulated. The rotors can be manipulatedat block 1112 based on the adjustments determined at block 1110.Manipulation of the rotors can include adjusting the position, speed ofrotation, and/or direction of rotation of one or more rotors of amagnetic rotor steering device.

In some cases, blocks 1106, 1108, and 1110 are not performed, andinstead the rotors are directly manipulated based on detections ofhorizontal deviation at block 1102 and/or detections of verticaldeviation at block 1104. For example, a light gate can be positioned ata desired edge point such that if the metal sheet deviates laterallybeyond the desired edge point, the light gate sends a signal to acontroller that manipulates the rotors, such as turning on rotors nearthe triggered light gate. Such a system would provide simple on/offfeedback control, rather than calculated feedback control (e.g., usingblocks 1106, 1108, and 1110).

The process 1100 can operate continuously and repeatedly.

FIG. 12 is a flow chart depicting a process 1200 for steering a metalstrip without feedback control according to certain aspects of thepresent disclosure. At block 1202, a metal strip is passed throughprocessing equipment having a desired passline. At block 1204, magneticrotors on opposite sides of a lateral centerline of a desired passlineor on opposite sides of a lateral centerline of a metal strip arerotated to induce changing magnetic fields proximate the magneticrotors. At block 1206, the lateral centerline of the metal strip isallowed to deviate away from the lateral centerline of the desiredpassline of the processing equipment towards at least one of therotating magnetic rotors. At block 1208, forces are generated in themetal strip by at least one of the changing magnetic fields (e.g., thechanging magnetic field proximate the magnetic rotor towards which themetal strip has moved). The forces generated at block 1208 can urge thelateral centerline of the metal strip towards the lateral centerline ofthe desired passline of the processing equipment. In some cases, theprocess 1200 can continue to repeat block 1206 and 1208 to keep themetal strip centered on the desired passline of the processingequipment.

FIG. 13A is an overhead view of a magnetic rotor steering device 1300including rotors 1310 longitudinally positionable above a metal strip1302 according to certain aspects of the present disclosure. Rotors 1310can be oriented such that its axis of rotation is parallel to thelongitudinal direction of travel of the strip 1302. The rotors 1310 canspan a portion of the lateral width of the strip 1302.

Various numbers of rotors 1310 can be used. In some cases, a singlerotor can be positioned approximately at the lateral centerline of adesired passline or at a lateral centerline of a metal strip and canrotate in either a clockwise or counter-clockwise direction depending ondetected deviation of the lateral centerline of the metal strip from thelateral centerline of the desired passline (e.g., lateral deviation fromthe desired passline). In some cases, the number of rotors 1310 can bean even number, as depicted in FIGS. 13A-13C. The multiple rotors 1310can be positioned with parallel axes of rotation. In some cases, norotor is positioned below the strip 1302 opposite rotors 1310. In somecases, one or more rotors is positioned below the strip 1302 oppositerotors 1310.

It can be desirable to cover more lateral width of the strip 1302 withrotors 1310 in order to provide increased vertical control of the strip1302 at that position.

FIG. 13B is a front view of the magnetic rotor steering device 1300 ofFIG. 13A including rotors 1310 longitudinally positionable above a metalstrip 1302 (optional rotors 1310 below the metal strip 1302 shown indashed lines) according to certain aspects of the present disclosure.The rotors 1310 above the metal strip 1302 are centered around thelateral centerline of a desired passline. The rotors 1310 below themetal strip 1302 are centered around the lateral centerline of thedesired passline. Laterally adjacent rotors 1310 may rotate in opposingdirections (e.g., clockwise or counter-clockwise as seen in FIG. 13B).Since the number of rotors 1310 is even, the net lateral forcesgenerated in the metal strip 1302 by the changing magnetic fieldsinduced by the rotors 1310 is zero when the metal strip 1302 is centeredon the desired passline.

FIG. 13C is a side view of the magnetic rotor steering device 1300 ofFIG. 13A including rotors 1310 longitudinally positionable above a metalstrip 1302 (with optional rotors 1310 shown in dashed lines below themetal strip 1302) according to certain aspects of the presentdisclosure.

FIG. 14 is a schematic, elevation diagram depicting a metal processingsystem 1400 including a magnetic rotor steering device 1404 used tosteer a metal strip 1402 prior to entering strip processing equipment1406 according to certain aspects of the present disclosure. The strip1402 can pass through the strip processing equipment 1406 in direction1410. Before entering the steering device 1404, the strip 1402 can bevertically offset from a vertical path 1408 (e.g., set of verticalcenterlines) of a desired passline. The steering device 1404 can correctthe vertical deviation, resulting in the strip 1402 entering the stripprocessing equipment 1406 in vertical alignment with the vertical path1408 of the desired passline. The steering device 1404 can be anysteering device as described herein.

FIG. 15 is a schematic, top view diagram depicting the metal processingsystem 1400 of FIG. 14 according to certain aspects of the presentdisclosure. The strip 1402 can pass through the strip processingequipment 1406 in direction 1410. Before entering the steering device1404, the strip 1402 can be horizontally offset from a desired lateralcenterline 1502 of a desired passline. The steering device 1404 cancorrect the horizontal deviation, resulting in the strip 1402 enteringthe strip processing equipment 1406 in horizontal alignment with thedesired lateral centerline 1502 of the desired passline. The steeringdevice 1404 can be any steering device as described herein.

FIG. 16 is a schematic, elevation diagram depicting a metal processingsystem 1600 including a magnetic rotor steering device 1604 used tosteer a metal strip 1602 after exiting strip processing equipment 1606according to certain aspects of the present disclosure. The strip 1602can pass through the strip processing equipment 1606 in direction 1610.After exiting the strip processing equipment 1606, the strip 1602 can bevertically offset from a vertical path 1608 of a desired passline. Thesteering device 1604 can correct the vertical deviation, resulting inthe strip 1602 becoming vertically aligned with the vertical path 1608of the desired passline despite problems imposed by or before the stripprocessing equipment 1606. The steering device 1604 can be any steeringdevice as described herein.

FIG. 17 is a schematic, top view diagram depicting the metal processingsystem 1600 of FIG. 16 according to certain aspects of the presentdisclosure. The strip 1602 can pass through the strip processingequipment 1606 in direction 1610. After exiting the strip processingequipment 1606, the strip 1602 can be horizontally offset from a desiredlateral centerline 1702 of a desired passline. The steering device 1604can correct the horizontal deviation, resulting in the strip 1602becoming horizontally aligned with the desired lateral centerline 1702of the desired passline. The steering device 1604 can be any steeringdevice as described herein.

FIG. 18 is an axonometric depiction of an applied-current magneticsteering apparatus 1800 according to certain aspects of the presentdisclosure. The applied-current magnetic steering apparatus 1800 passesa metal strip 1802 through a magnetic field and applies an electricalcurrent to at least a portion of the metal strip 1802 in order to induceforce perpendicular to the magnetic field and direction of the electriccurrent. The magnetic field can be generated by any suitable technique,such as electromagnets or permanent magnets. The direct current (DC)electrical current can be applied to the metal strip 1802 by anysuitable technique, such as graphite brushes, conductive rollers, orother techniques.

The applied-current magnetic steering apparatus 1800 can include a pairof permanent magnets 1808 that are held stationary on pair of lateralsupports 1804 (e.g., a top frame above the vertical centerline 1822 of adesired passline of the metal strip 1802 and a bottom frame below thevertical centerline 1822 of the desired passline). The permanent magnets1808 can present opposite magnetic poles to the vertical centerline 1822of the desired passline, thus generating a magnetic field 1820 throughthe vertical centerline 1822 of the desired passline. In some cases, theframe can be positioned with respect to a vertical centerline of themetal strip 1802 instead of a vertical centerline 1822 of a desiredpassline. The magnetic field 1820 can be a uniform magnetic field acrossthe width of the metal strip 1802, although a non-uniform magnetic fieldcan be used in some cases. In some cases, magnets 1808 are placed toonly generate a magnetic field near the edges of the metal strip 1802.In some cases, one or more permanent magnets 1808 are placed near themetal strip 1802 on only one side of the metal strip 1802 (e.g., onlythe top or only the bottom).

The lateral supports 1804 can be supported by a pair of verticalsupports 1806. Linear actuators 1810 on the vertical supports 1806 cancontrol the vertical distance of one or both vertical supports 1806 fromthe metal strip 1802. Linear actuators 1810 can control the verticalpositioning of each lateral support 1804 (e.g., top support and bottomsupport) separately or together. In some cases, some linear actuators1810 can control the gap between the lateral supports 1804, while otherlinear actuators 1810 can control the vertical displacement of acenterline between the top and bottom lateral supports 1804. Anysuitable number of linear actuators 1810 can be used. Any suitablelinear actuators 1810 can be used, such as motor-and-screw combinationsor hydraulic actuators.

Each vertical support 1806 can support one or more electrodes 1812,1814, although the one or more electrodes 1812, 1814 can be supported byother equipment. The one or more electrodes 1812, 1814 can apply acurrent through the metal strip 1802. Electrodes 1812, 1814 can bepositioned to apply a current through the metal strip 1802 along theedges of the metal strip 1802 within the magnetic field 1820, across thewidth of the metal strip 1802 within the magnetic field 1820, or anycombination thereof. In some cases, each vertical support 1806 cansupport one positive electrode 1812 and one negative electrode 1814. Thepositive electrode 1812 and the negative electrode 1814 can bepositioned on opposite sides of a plane formed between the lateralsupports 1804. In some cases, a positive electrode 1812 of one verticalsupport 1806 can be positioned laterally across the metal strip 1802from a negative electrode 1814 of another vertical support 1806,although it can be positioned laterally across the metal strip 1802 froma positive electrode 1812 of another vertical support 1806 in othercases.

In some cases, electrodes 1812, 1814 are located elsewhere, such as onequipment other than vertical supports 1806 or lateral supports 1804,including at any distance from the other elements (e.g., permanentmagnets 1808) of the applied-current magnetic steering apparatus 1800.Electrodes 1812, 1814 can be placed anywhere in contact with the metalstrip 1802 as long as current flows through the magnetic field 1820generated by the applied-current magnetic steering apparatus 1800. Forexample, a positive electrode 1812 can be placed near the beginning ofone or more pieces of metal strip processing equipment, while a negativeelectrode 1814 is placed near the end of the one or more pieces of metalstrip processing equipment, with the permanent magnets 1808 generating amagnetic field 1820 at a location anywhere between the electrodes 1812,1814. In some cases, electrodes 1812, 1814 can be placed at locationswhere the metal strip 1802 is under greater tension than and/or iscooler than where the metal strip 1802 is being steered (e.g., where themagnetic field 1820 intersects the metal strip 1802). Contacting themetal strip 1802 with electrodes 1812, 1814 when the metal strip isunder high tension and/or at a relatively cold temperature (e.g., at ornear room temperature, after being cooled in a cooling section of acontinuous annealing line, and/or before being heated in a furnacesection of a continuous annealing line) may avoid contact-based damageto the metal strip 1802. The permanent magnets 1808 may be placedanywhere that steering is desired.

Each electrode 1812, 1814 can include any suitable mechanism fortransmitting current to the metal strip 1802. In some cases, theelectrodes 1812, 1814 include graphite brushes, although othermechanisms can be used to transmit current to the metal strip 1802. Insome cases, a roller is positioned to contact the metal strip 1802 at oradjacent the electrodes 1812, 1814 to maintain contact between the metalstrip 1802 and the electrodes 1812, 1814 to minimize arcing. The rollercan be biased (e.g., with a spring) to ensure contact with the metalstrip 1802 prior to application of electrical current. Theapplied-current magnetic steering apparatus 1800 can be useful forpreventing over-travel of the metal strip (e.g., movement of the lateralcenterline of the metal strip beyond a desired distance from the lateralcenterline of the desired passline), as the electrodes 1812, 1814 can bepositioned to contact the metal strip 1802, and thus produce acorrective force, only when the metal strip 1802 has deviated from thedesired passline by more than a preset tolerance.

The current applied through the metal strip 1802 can be DC. Electrodes1812, 1814 can be connected to a power source through cables 1816. Insome cases, no current would be applied to the metal strip 1802 until itis determined that steering is needed (e.g., correction is needed). Theapplied-current magnetic steering apparatus 1800 can include any of thesensing equipment disclosed herein with regards to the magnetic rotorsteering devices (e.g., permanent-magnet magnetic rotor steering device700 of FIG. 7) to determine when steering is needed.

In some cases, multiple sets of permanent magnets 1808 are used atlongitudinally offset locations to generate multiple magnetic fields1820 at longitudinally offset locations. In such cases, electrodes 1812,1814 can be located before the first set of permanent magnets 1808 andafter the last set of permanent magnets 1808, such that the currentflowing through the metal strip 1802 passes through each of the multiplemagnetic fields 1820. In such cases, steering of the metal strip 1802can be controlled at various locations by controlling the magnetic field1820 at each particular location. The magnetic field 1820 at aparticular location can be controlled by adjusting the vertical distancebetween the permanent magnets 1808 and the metal strip 1802 at thatparticular location. For example, to apply more steering force at afirst set of magnets and less steering force at a second set of magnets,the same current can be applied through the metal strip 1802 and thefirst set of magnets can be moved vertically closer to the metal stripthan the second set of magnets. Current can be held constant orcontrolled simultaneously. Each set of magnets can be associated withits own set of sensing equipment to control the vertical distance ofthat particular set of magnets with respect to the metal strip.

In some cases, an applied-current magnetic steering apparatus 1800includes permanent magnets 1808 oriented in a direction other thanlaterally with respect to the metal strip 1802. For example, anapplied-current magnetic steering apparatus 1800 can include permanentmagnets 1808 oriented longitudinally with respect to the metal strip1802, above and below the edges of the metal strip 1802, to generatemagnetic fields 1820 through the edges of the metal strip 1802. Suchcases can be used, for example, to apply steering force at the edges ofa metal strip 1802 for a longitudinal distance (e.g., the length of thepermanent magnets 1808 or longitudinal length of the resultant magneticfields 1820).

FIG. 19 is a front view of the applied-current magnetic steeringapparatus 1800 of FIG. 18 according to certain aspects of the presentdisclosure. The applied-current magnetic steering apparatus 1800 isshown with two vertical supports 1806 supporting two lateral supports1804. Permanent magnets 1808 are supported by the lateral supports 1804above and below the metal strip 1802. Electrodes 1812, 1814 contact themetal strip 1802 at or near the edges of the metal strip 1802. Linearactuators 1810 can adjust the vertical positioning of the lateralsupports 1804 as described above.

Cables 1816 couple the electrodes 1814 to a power supply 1902. The powersupply 1902 can be any power supply suitable for providing electriccurrent to through the metal strip 1802.

FIG. 20A is a top view of the applied-current magnetic steeringapparatus 1800 of FIG. 18 according to certain aspects of the presentdisclosure. The applied-current magnetic steering apparatus 1800 isshown with two vertical supports 1806 supporting lateral supports 1804.Electrodes 1812, 1814 contact the metal strip 1802 at or near the edgesof the metal strip 1802. Linear actuators 1810 can adjust the verticalpositioning of the lateral supports 1804 as described above. Cables 1816provide power to the electrodes 1814 for applying an electrical currentto the metal strip 1802.

In some cases, an applied-current magnetic steering apparatus includessafety equipment to ensure that when a break occurs in the metal strip1802, the current being applied by any electrode would not be able tofind a path through ground that can damage other equipment or pose ahazard. In some cases, grounding equipment (e.g., conducting rollers)can be located before and/or after the applied-current magnetic steeringapparatus in order to ensure a path through ground exists that would notdamage other equipment or pose a hazard. In some cases, circuit breakerequipment (e.g., ground-fault interrupt circuit breakers) can be used toensure the safety of the apparatus in the event of an unexpected load.In some cases, strip break detection equipment (e.g., visual orconducting) can be placed before the applied-current magnetic steeringapparatus such that if a break is detected, the applied-current magneticsteering apparatus can be shut down or disabled before the break reachesthe applied-current magnetic steering apparatus. Other types of safetyequipment can be used.

The applied-current magnetic steering apparatus as described herein canbe used wherever steering is needed, such as in place of the non-contactmagnetic rotor steering device 1604 of FIGS. 14-17. The applied-currentmagnetic steering apparatus can also be used with detection equipment asdescribed above with reference to the various steering devices, such asin the feedback control process 1100 of FIG. 11. When applying theapplied-current magnetic steering apparatus to the feedback controlprocess 1100 of FIG. 11, determining adjustments to the permanent magnetrotors at block 1110 and manipulating of the rotors at block 1112 wouldbe replaced with determining adjustments to the applied current and/ormagnetic field (e.g., through vertical adjustments to the lateralsupports supporting the permanent magnets) and manipulating the appliedcurrent and/or magnetic field, respectively. The applied-currentmagnetic steering apparatus can also be used at any suitable location ina continuous annealing line, such as the continuous annealing line 900of FIG. 9, wherein each or any of the magnetic rotor steering devices902 could be an applied-current magnetic steering apparatus.

FIG. 20B is a top view of an applied-current magnetic steering apparatus2000 according to certain aspects of the present disclosure. Theapplied-current magnetic steering apparatus 2000 is similar to theapplied-current magnetic steering apparatus 1800 of FIGS. 18-20, howeverwith edge-located magnets 2008 instead of the magnets 1808 of FIG. 18.

The applied-current magnetic steering apparatus 1800 can include a pairof vertical supports 1806 supporting electrodes 1812, 1814. Eachvertical support 1806 can support a set of permanent magnets 2008 aboveand below the metal strip 1802 along the edge of the metal strip 1802between electrodes 1812, 1814.

FIG. 21 is a front view of a magnetic rotor steering device 2100according to certain aspects of the present disclosure. The magneticrotor steering device 2100 can include a set of rotors 2110 coupled tohorizontal supports 2104. Each rotor 2110 can be a permanent magnet orelectromagnet rotor, as disclosed herein. The magnetic rotor steeringdevice 2100 can be similar to the magnetic rotor steering device 100 ofFIG. 1, however with rotors 2110 mounted from above and below the metalstrip 2102 such that no structure remains between vertically adjacentrollers (e.g., the two leftmost or two rightmost rollers as seen in FIG.21) for the metal strip 2102 to crash into should the metal strip strayfar enough from the lateral centerline 2106 of a desired passline. Therotors 2110 can be supported from the horizontal supports 2104 by rotorarms 2108.

In some cases, rotor arms 2108 are adjusted to manipulate the rotor 2110in a vertical direction 2118 (e.g., upwards or downwards). In somecases, rotor arms 2108 are movable along the horizontal support 2104 tomanipulate the rotor in a horizontal direction 2116 (e.g., away from ortowards the lateral centerline 2106 of the desired passline). In somecases, feedback from a control system or feedback sensors can adjust theposition of the rotor 2110. In some cases, however, the rotor arms 2108may hold the rotor 2110 stationary (e.g., horizontally and verticallystationary) with respect to the horizontal support 2104.

In some cases, a motor or other driver rotates each rotor 2110 in aclockwise 2114 or counterclockwise 2112 direction. The motors or otherdrivers used to rotate the rotors of the steering device 2100 or othersteering devices disclosed herein can be or can include a variable speeddriver for providing adjustment to the rotational speed of the rotor.For example, a variable frequency driver can be used to adjust speed ofan alternating current (AC) motor. Rotational speed may be controlledusing preset values or through feedback from feedback sensors. In somecases, the motor or other driver may provide a steady force to rotatethe rotor, without the need for any variable speed controls or sensorfeedback.

In some cases, a motor or other driver can rotate rotors 2110 in anappropriate direction such that the surface of each rotor nearest thevertical centerline 2120 of the desired passline moves towards thelateral centerline 2106 of the desired passline. In other words,starting at the top left and continuing clockwise as depicted in FIG.21, the first and third rotors 2110 can spin in a counterclockwisedirection 2112, while the second and fourth rotors 2110 spin in aclockwise direction 2114.

FIG. 22 is a cutaway side view of a furnace 2200 into which a magneticrotor steering apparatus can be fit according to certain aspects of thepresent disclosure. In some cases, it can be desirable to locate themagnetic rotor steering apparatus in a furnace zone or cooling zone,such as described above with reference to FIG. 9. In some cases, it canbe desirable to locate the magnetic rotor steering apparatus outside ofthe housing or outer walls 2202 of the furnace 2200 of the furnace zone,but sufficiently adjacent the metal strip 2210 to steer the metal strip2210.

A furnace 2200 in a furnace zone can include an outer wall 2202enclosing several air nozzles 2204. A passline gap 2214 exists betweenupper and lower air nozzles 2204, through which the metal strip 2210passes. The air nozzles 2204 can provide sufficient airflow to maintainthe metal strip 2210 at or near a vertical path 2212 of the desiredpassline. The metal strip 2210 may take a sinusoidal shape when passingthrough the furnace 2200.

A gap 2216 may exist between adjacent air nozzles 2204 of an existingfurnace 2200. Cuts can be made into the outer walls 2202 at points 2206to remove a section 2208 of the outer wall 2202. Once the section 2208has been removed, a recessed section can be installed in the outer walls2202, as seen in FIGS. 23 and 24.

FIG. 23 is a cutaway side view of a furnace 2300 that has been modifiedto receive a magnetic rotor steering apparatus. The outer walls 2202have a recessed section 2308 installed where a section had been removed.The recessed section can include vertical walls 2318 and a horizontalwall 2320. The horizontal wall 2320 can be spaced apart from thevertical path 2312 of the desired passline by approximately the samedistance as the end of the nozzles 2304, thus maintaining approximatelythe same passline gap 2314 as before modifications.

The walls 2318, 2320 of the recessed section 2308 can provide thermalinsulation to maintain heat in the furnace 2300. In some cases, thevertical walls 2318 can provide more thermal insulation than thehorizontal wall 2320. In some cases, the horizontal wall 2320 can bethinner than the vertical walls 2318, to allow the magnetic rotorsteering device to be positioned close to the vertical path 2312 of thedesired passline of the metal strip 2310 passing through the furnace2300.

In some cases, optional rollers 2322 can be installed adjacent therecessed section 2308 within the passline gap 2314. The rollers 2322 canbe free to rotate or can rotate at the speed of the metal strip 2310moving through the furnace 2300 so that if the metal strip 2310 movestoo far away from the vertical path 2312 of the desired passline, themetal strip 2310 will contact the roller 2322 instead of crashing intothe recessed section 2308.

Once a furnace 2300 has been modified to include a recessed section2308, a magnetic rotor steering device can be placed in the U space ofthe recessed section 2308, as seen in FIG. 24.

FIG. 24 is a cutaway side view depicting a magnetic rotor steeringapparatus 2424 incorporated into a furnace 2400 according to certainaspects of the present disclosure. The furnace 2400 can include arecessed section 2408 in the outer walls 2402 of the furnace 2400. Therecessed section 2408 can be originally built into the outer walls 2402of the furnace 2400, or can be added to an existing furnace throughmodification, such as described above with reference to FIGS. 22-23. Themetal strip 2410 can move through the furnace 2400 at or near a verticalpath 2412 of the desired passline, between air nozzles 2404.

In some cases, the vertical walls 2418 of the recessed section 2408 canhave a sufficient thickness or be made of a material sufficient toprovide a high degree of thermal insulation, to maintain heat within thefurnace 2400 and reduce the amount of heat transfer from the furnace2400 to the magnetic rotor steering apparatus 2424. In some cases, thehorizontal wall 2420 of the recessed section 2408 can be thinner thanthe vertical walls 2418 to allow the rotor 2426 of the magnetic rotorsteering apparatus 2424 to be positioned as closely as possible to themetal strip 2410. In some cases, the horizontal wall 2420 of therecessed section 2408 can be made from a non-electrically conductivematerial. In some cases, the horizontal wall 2420 of the recessedsection 2408 can be made from an electrically conductive material,optionally with slits for reducing eddy currents, as described abovewith reference to the rotor shield 120 of FIG. 5.

FIG. 25 is a cutaway side view depicting a magnetic rotor steeringapparatus 2524 incorporated into a furnace 2500 at a furnace entrance2550 according to certain aspects of the present disclosure. The furnace2500 can include a recessed section 2508 in the outer walls 2502 of thefurnace 2500 at the furnace entrance 2550. The recessed section 2508 canbe originally built into the outer walls 2502 of the furnace 2500, orcan be added to an existing furnace through modification, such asdescribed above with reference to FIGS. 22-23. The metal strip 2510 canmove through the furnace 2500 at or near a vertical path 2512 of thedesired passline, between air nozzles 2504.

When implemented at a furnace entrance 2550, the recessed section 2508can include a vertical wall 2518 and a horizontal wall 2520. In somecases, the side opposite the horizontal wall 2520 from the vertical wall2518 can be left open or semi-open (e.g., having a vertical wall sectionthat is smaller than vertical wall 2518), allowing easier access to themagnetic rotor steering apparatus 2524.

FIG. 26 is a cutaway side view depicting a magnetic rotor steeringapparatus 2624 incorporated into a furnace 2600 at a furnace exit 2650according to certain aspects of the present disclosure. The furnace 2600can include a recessed section 2608 in the outer walls 2602 of thefurnace 2600 at the furnace exit 2650. The recessed section 2608 can beoriginally built into the outer walls 2602 of the furnace 2600, or canbe added to an existing furnace through modification, such as describedabove with reference to FIGS. 22-23. The metal strip 2610 can movethrough the furnace 2600 at or near a vertical path 2612 of the desiredpassline, between air nozzles 2604.

When implemented at a furnace exit 2650, the recessed section 2608 caninclude a vertical wall 2618 and a horizontal wall 2620. In some cases,the side opposite the horizontal wall 2620 from the vertical wall 2618can be left open or semi-open (e.g., having a vertical wall section thatis smaller than vertical wall 2618), allowing easier access to themagnetic rotor steering apparatus 2624.

FIG. 27 is a front view of a magnetic rotor steering device 2700 havingsecondary rotors according to certain aspects of the present disclosure.The magnetic rotor steering device 2700 can include multiple rotors 2710that are permanent magnet or electromagnet rotors, as disclosed herein.As depicted in FIG. 27, each rotor 2710 is mounted to horizontalsupports 2704 located above and below the metal strip 2702 similar toFIG. 21. However, in some cases, rotors 2710 are mounted to verticalsupports, such as depicted in FIG. 1. Rotors 2710 can be supported byrotors arms 2708.

The magnetic rotor steering device 2700 can include primary rotors 2730and secondary rotors 2732. Primary rotors 2730 can be positioned closerto the lateral centerline 2706 of a desired passline than the secondaryrotors 2732. Secondary rotors 2732 can be spaced a distance 2740 apartfrom the primary rotors 2730. The distance 2740 can be sufficient toavoid magnetic interference between the adjacent rotors 2710 (e.g., suchthat rotation of a secondary rotor 2732 adjacent a primary rotor 2730reduces the efficiency of rotation of the primary rotor 2730 by at leastless than 20%, 15%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, or 1%). If anyof the primary rotors 2730 fail to maintain the metal strip 2702laterally aligned with the lateral centerline 2706 of a desired passlineor within a desired lateral offset therefrom (e.g., due to failure ofthe primary rotor 2730 or any motor attached thereto or due tooverwhelmingly strong lateral forces imposed on the metal strip 2702 byother factors), the secondary rotors 2732 can provide additional forceto urge the metal strip 2702 towards the lateral centerline 2706 of adesired passline.

As depicted in FIG. 27, each of the secondary rotors 2732 is supportedby rotor arms 2708 separate from the primary rotors 2730, however thatneed not be the case. In some cases, a secondary rotor 2732 can becoupled to the rotor arm 2708 of a primary rotor 2730. Primary rotors2730 and secondary rotors 2732 can be powered or rotated by separatemotors, however that need not be the case. In some cases, a single motorcan power or rotate both a secondary rotor 2732 and a primary rotor2730.

Each primary rotor 2730 can be positioned along a primary rotor plane2734 (e.g., such that the primary rotor 2730 rotates around an axis ofrotation found on the primary rotor plane 2734). Each secondary rotor2732 can be positioned along a secondary rotor plane 2736 (e.g., suchthat the secondary rotor 2732 rotates around an axis of rotation foundon the secondary rotor plane 2736). Therefore, the secondary rotorplanes 2736 are located opposite the primary rotor planes 2734 from thelateral centerline of a desired passline of the metal strip 2702 (e.g.,the secondary rotor planes 2736 are spaced a distance apart from theprimary rotor planes 2734 away from the lateral centerline of a desiredpassline of the metal strip 2702). A primary rotor set 2742 can includeone or more primary rotors 2730 located on a single primary rotor plane2734. A secondary rotor set 2744 can include one or more secondaryrotors 2732 located on a single secondary rotor plane 2736. FIG. 27depicts two primary rotors sets 2742 and two secondary rotor sets 2744,each having two rotors 2710 (e.g., a top rotor 2710 positioned above themetal strip 2702 and a bottom rotor 2710 positioned below the metalstrip 2702).

The primary rotor planes 2734 and secondary rotor planes 2736 can beadjustable by adjusting the rotor arms 2708 along the horizontalsupports 2704. In some cases, the primary rotor planes 2734 andsecondary rotor planes 2736 can be fixed. As depicted in FIG. 27, theprimary rotor planes 2734 can be located (e.g., fixed or adjustable) ator around the lateral edges 2738 of the metal strip 2702. As usedherein, reference to a distance of a rotor plane from a lateral edge mayrefer to the distance between the rotor plane and a lateral edge of ametal strip passing with its lateral centerline aligned to the lateralcenterline of the desired passline. In some cases, the primary rotorplanes 2734 can be located within a rotor's radius of the lateral edges2738. In some cases, the primary rotor plane 2734 can be distally spaced(e.g., away from the lateral centerline 2706 of the desired passline) adistance apart from the lateral edge 2738, such as less than a rotor'sradius, approximately a rotor's radius, or more than a rotor's radius.

The primary rotors 2730 and secondary rotors 2732 can operatecontinuously, with a motor or other driver rotating each rotor 2710 in aclockwise 2714 or counterclockwise 2712 direction. In some cases,secondary rotors 2732 can spin up and operate only once the metal strip2702 has laterally moved away from the lateral centerline 2706 of thedesired passline sufficiently.

In some cases, the motor or other driver can rotate the rotors 2710 inan appropriate direction such that the surface of each rotor nearest thevertical centerline 2720 of the desired passline moves towards thelateral centerline 2706 of the desired passline. In other words,starting at the top left and continuing clockwise as depicted in FIG.27, the first, second, fifth and sixth rotors 2710 can spin in acounterclockwise direction 2712, while the third, fourth, seventh, andeighth rotors 2710 spin in a clockwise direction 2714.

The motor or other driver can be or can include a variable speed driverfor providing adjustment to the rotational speed of the rotor 2710. Forexample, a variable frequency driver can be used to adjust speed of analternating current (AC) motor. Rotational speed may be controlled usingpreset values or through feedback from feedback sensors. In some cases,the motor or other driver may provide a steady force to rotate the rotor2710, without the need for any variable speed controls or sensorfeedback.

Secondary rotors 2732 and primary rotors 2734 can be the same ordifferently sized and can include the same or different levels ofmagnetization (e.g., by selecting the number, sizes, and types ofmagnets within the rotor). Secondary rotors 2732 and primary rotors 2734can operate at the same or different rotational speeds. In some cases,the secondary rotors 2732 can operate at speeds greater than the speedsof the primary rotors 2730.

While FIG. 27 depicts primary rotors 2730 and secondary rotors 2732, amagnetic rotor steering device 2700 can include any number of furtherlaterally spaced apart rotors, such as tertiary, quaternary, and thelike.

FIG. 28 is a front view of a magnetic steering device 2800 for steeringa metal strip 2802 according to certain aspects of the presentdisclosure. The metal strip 2802 can be moving in a strip traveldirection that is perpendicular to plane 2810 (e.g., towards the viewerof FIG. 28). One or more magnets 2804 (e.g., permanent magnets orelectromagnets) can be positioned above and/or below the metal strip2802. In some cases, the one or more magnets 2804 includes a first setof magnets 2812 positioned opposite a centerline 2814 of the metal strip2802 from a second set of magnets 2816. Magnets 2804 can all be locatedin a common plane 2810.

The magnets 2804 can be moved and/or translated in various directionswithin the plane 2810. Suitable actuators (e.g., linear actuators)and/or linkages can be used to move the magnets 2804 along a path 2806forming a closed loop. The path 2806 can be of any suitable shape,including circular, ellipsoidal, ovoid, generally rectangular, orotherwise. The path 2806 can include a section close to a center,horizontal plane 2818 of the metal strip and a section spaced furtherapart from that plane 2818, such that the magnet 2804 is closer to themetal strip 2802 when moving in a first lateral direction (e.g., left toright) and further from the metal strip 2802 when moving in an oppositelateral direction (e.g., right to left). The movement of the magnet 2804when closest the metal strip 2802 can create a force urging the metalstrip 2802 to move laterally (e.g., in the direction of the movement ofthe magnet 2804 when closest the metal strip 2802).

In some cases where electromagnets are used, a path 2806 can be alinear, arcuate, or curved path between two points. Since such a pathbetween two points (e.g., not a closed loop) may involve the magnet 2804passing closest to the metal strip 2802 in both a first direction and anopposite direction, the electromagnet can be actuated to turn on whenpassing in a first direction and turn off or be mostly attenuated whenpassing in the opposite direction, thus inducing a net force in thefirst direction.

Magnetic steering device 2800 can be used with sensors, controllers, andother elements similar to those described herein with reference tomagnetic rotors, as appropriate.

The foregoing description of the examples, including illustratedexamples, has been presented only for the purpose of illustration anddescription and is not intended to be exhaustive or limiting to theprecise forms disclosed. Numerous modifications, adaptations, and usesthereof will be apparent to those skilled in the art.

As used below, any reference to a series of examples is to be understoodas a reference to each of those examples disjunctively (e.g., “Examples1-4” is to be understood as “Examples 1, 2, 3, or 4”).

Example 1 is a magnetic steering apparatus, comprising: a first rotorset comprising at least a first magnetic rotor that rotates about arespective first axis of rotation; a second rotor set comprising atleast a second magnetic rotor that rotates about a respective secondaxis of rotation, wherein the first axis of rotation is not collinearwith the second axis of rotation, wherein each magnetic rotor of thefirst and second rotor sets intersects a plane perpendicular to adirection of travel of a moving metal strip, and wherein each of thefirst axis of rotation and the second axis of rotation are offset from alateral centerline of the moving metal strip at the plane, and; one ormore rotor motors coupled to the first and second magnetic rotors torotate the magnetic rotors and induce changing magnetic fields proximatethe magnetic rotors, wherein at least one of the changing magneticfields generates a force in the moving metal strip to steer the movingmetal strip as the moving metal strip passes through the at least onemoving magnetic field.

Example 2 is the apparatus of example 1, wherein each of the magneticrotors includes one or more permanent magnets.

Example 3 is the apparatus of examples 1 or 2, wherein the first axis ofrotation is positionable opposite the lateral centerline of the movingmetal strip from the second axis of rotation, and wherein the first andthe second axes of rotation are laterally spaced apart by a distancethat is greater than a width of the moving metal strip.

Example 4 is the apparatus of examples 1-3, wherein the first rotor setcomprises a third magnetic rotor and the second rotor set comprises afourth magnetic rotor, wherein the first and third magnetic rotors arepositioned horizontally opposite the lateral centerline of the movingmetal strip from the second and fourth magnetic rotors, wherein thefirst and third magnetic rotors are vertically spaced apart from oneanother, and wherein the second and fourth magnetic rotors arevertically spaced apart from one another.

Example 5 is the apparatus of examples 1-4, further comprising: one ormore actuators coupled to one or more magnetic rotors of the first rotorset and the second rotor set to adjust vertical, horizontal, or verticaland horizontal positioning of the one or more magnetic rotors.

Example 6 is the apparatus of example 5, further comprising a controllercoupled to a sensor and the one or more actuators to adjust thevertical, horizontal, or vertical and horizontal positioning of the oneor more magnetic rotors in response to a signal from the sensor.

Example 7 is the apparatus of examples 1-6, further comprising, for eachmagnetic rotor of the first rotor set and the second rotor set, a rotorshield surrounding the magnetic rotor, wherein the rotor shield definesan enclosed space.

Example 8 is the apparatus of example 7, further comprising, for eachmagnetic rotor of the first rotor set and the second rotor set, a sourceof coolant fluidly coupled to the enclosed space for removing heat fromthe magnetic rotor.

Example 9 is the apparatus of examples 1-8, further comprising: a thirdrotor set having at least one additional magnetic rotor that rotatesabout a respective additional axis of rotation and intersects the plane,wherein the additional axis of rotation of each additional magneticrotor of the third rotor set is laterally offset from each of the firstaxis of rotation and the second axis of rotation at the plane.

Example 10 is a magnetic steering apparatus, comprising: a first rotorset including a first top rotor positioned vertically opposite a desiredpassline from a first bottom rotor, wherein each of the first top rotorand the first bottom rotor includes one or more permanent magnets, andwherein each of the first top rotor and the first bottom rotor includesa motor coupled to the rotor for rotating the rotor to induce a changingmagnetic field proximate the rotor; a second rotor set including asecond top rotor positioned vertically opposite the desired passlinefrom a second bottom rotor, wherein each of the second top rotor and thesecond bottom rotor includes one or more permanent magnets, wherein eachof the second top rotor and the second bottom rotor includes a motorcoupled to the rotor to induce a changing magnetic field proximate therotor, and wherein axes of rotation of the first top rotor and firstbottom rotor are laterally spaced apart from and located opposite acenterline of a desired passline from axes of rotation of the second toprotor and second bottom rotor such that one or more of the changingmagnetic fields generate force in a moving metal strip travelingproximate the first rotor set and the second rotor set to steer acenterline of the moving metal strip towards the centerline of thedesired passline.

Example 11 is the apparatus of example 10, wherein: the first top rotorand the first bottom rotor are coupled to a first vertical support; thesecond top rotor and the second bottom rotor are coupled to a secondvertical support; and the first vertical support and second verticalsupport are both horizontally positionable along a horizontal support.

Example 12 is the apparatus of examples 10 or 11, wherein the first toprotor and the second top rotor are horizontally positionable along a tophorizontal support, and wherein the first bottom rotor and the secondbottom rotor are horizontally positionable along a bottom horizontalsupport.

Example 13 is the apparatus of example 12, wherein the first top rotorand the second top rotor are vertically positionable with respect to thetop horizontal support, and wherein the first bottom rotor and thesecond bottom rotor are vertically positionable with respect to thebottom horizontal support.

Example 14 is the apparatus of examples 10-13, further comprising, foreach rotor of the first rotor set and the second rotor set, a rotorshield surrounding the rotor, wherein the rotor shield defines anenclosed space.

Example 15 is the apparatus of example 14, further comprising, for eachrotor of the first rotor set and the second rotor set, a source ofcoolant fluidly coupled to the enclosed space for removing heat from therotor.

Example 16 is the apparatus of examples 10-15, wherein a lateraldistance between the axes of rotation of the first top rotor and firstbottom rotor and the axes of rotation of the second top rotor and secondbottom rotor is within a 5% deviation of a width of the metal strip.

Example 17 is the apparatus of examples 10-16, wherein the lateraldistance between the axes of rotation of the first top rotor and firstbottom rotor and the axes of rotation of the second top rotor and secondbottom rotor is greater than a width of the metal strip.

Example 18 is the apparatus of example 17, wherein the lateral distancebetween the axes of rotation of the first top rotor and first bottomrotor and the axes of rotation of the second top rotor and second bottomrotor is greater than a width of the metal strip by at least a sum ofthe radii of the first top rotor and the second top rotor.

Example 19 is the apparatus of example 17, wherein the lateral distancebetween the axes of rotation of the first top rotor and first bottomrotor and the axes of rotation of the second top rotor and second bottomrotor is greater than a width of the metal strip by at least half of thewidth of the metal strip.

Example 20 is the apparatus of examples 10-19, wherein the centerline ofthe metal strip is a lateral centerline of the metal strip; and whereinthe centerline of the desired passline is a lateral centerline of thedesired passline.

Example 21 is a metal processing system, comprising: processingequipment for receiving a moving metal strip, the processing equipmenthaving a desired passline; and a magnetic rotor steering devicepositionable proximate the moving metal strip, the magnetic rotorsteering device comprising at least one magnetic rotor, the at least onemagnetic rotor being rotatable to induce a changing magnetic field atthe moving metal strip suitable to generate a force in the moving metalstrip to steer a lateral centerline of the moving metal strip towards alateral centerline of the desired passline of the processing equipment.

Example 22 is the system of example 21, wherein the processing equipmentis selected from a furnace zone and a cooling zone of a continuousannealing line.

Example 23 is the system of examples 21 or 22, wherein the magneticrotor steering device is positioned adjacent at least one of an entranceof the processing equipment and an exit of the processing equipment.

Example 24 is the system of examples 21 or 22, wherein the magneticrotor steering device is positioned between an entrance of theprocessing equipment and an exit of the processing equipment.

Example 25 is the system of examples 21-24, wherein the processingequipment includes an outer wall having a recessed section, wherein themagnetic rotor steering device is positioned at least partially withinthe recessed section.

Example 26 is the system of examples 21-25, further comprising: one ormore actuators coupled to the at least one magnetic rotor to adjustvertical, horizontal, or vertical and horizontal positioning of the atleast one magnetic rotor; and a controller coupled to a sensor and theone or more actuators to adjust the vertical, horizontal, or verticaland horizontal positioning of the at least one magnetic rotors inresponse to a signal from the sensor.

Example 27 is the system of examples 21-26, wherein each of the at leastone magnetic rotor includes one or more permanent magnets.

Example 28 is the system of examples 21-27, wherein the at least onemagnetic rotor includes a first set of rotors adjacent a first edge ofthe moving metal strip and a second set of rotors adjacent a second edgeof the moving metal strip, wherein the first edge is located opposite alateral centerline of the moving metal strip from the second edge.

Example 29 is the system of example 28, wherein one of the first set ofrotors is positioned opposite the moving metal strip from another of thefirst set of rotors, and wherein one of the second set of rotors ispositioned opposite the moving metal strip from another of the secondset of rotors.

Example 30 is the system of examples 21-29, wherein the moving metalstrip is unsupported by a physically contacting support for a section ofthe processing equipment, and wherein the magnetic rotor steering deviceis positioned within the section.

Example 31 is the apparatus of examples 21-30, wherein the centerline ofthe metal strip is a lateral centerline of the metal strip; and whereinthe centerline of the desired passline is a lateral centerline of thedesired passline.

Example 32 is a method of steering a moving metal strip, comprising:passing a metal strip adjacent at least one magnetic rotor, the at leastone magnetic rotor being spaced apart from a surface of the metal strip;rotating the at least one magnetic rotor to induce a changing magneticfield at the moving metal strip; and generating a force in the movingmetal strip in response to inducing the changing magnetic field.

Example 33 is the method of example 32, further comprising: sensing aposition of the metal strip; and controlling an actuator coupled to theat least one magnetic rotor based on the sensed position, whereincontrolling the actuator includes adjusting at least one of a horizontalor a vertical position of the at least one magnetic rotor.

Example 34 is the method of examples 32 or 33, further comprising:accessing a pre-determined parameter of the strip; and controlling anactuator coupled to the at least one magnetic rotor based on thepre-determined parameter, wherein controlling the actuator includesadjusting at least one of a horizontal or a vertical position of the atleast one magnetic rotor.

Example 35 is the method of example 34, wherein accessing thepre-determined parameter of the strip includes accessing at least oneselected from the group consisting of strip width, strip thickness, andlocation of a lateral centerline of a desired passline.

Example 36 is the method of examples 32-35, further comprising: sensinga position of the metal strip; and controlling a speed of rotation ofthe at least one magnetic rotor coupled based on the sensed position.

Example 37 is the method of examples 32-36, wherein passing the metalstrip includes passing the metal strip at a tension at or below 40 Mpa.

Example 38 is the method of examples 32-37, wherein passing the metalstrip includes passing the metal strip at a tension at or below 5 Mpa.

Example 39 is a method of modifying processing equipment for magneticrotor steering, the method comprising: removing a section of outer wallfrom the processing equipment; replacing the section of outer wall witha recessed section having a horizontal wall and at least one verticalwall; and positioning a magnetic rotor of a magnetic rotor steeringdevice within the recessed section such that the magnetic rotor isopposite the horizontal wall from an interior of the processingequipment.

Example 40 is the method of example 39, further comprising: rotating themagnetic rotor to induce a changing magnetic field within the interiorof the processing equipment, wherein the changing magnetic field issufficient to generate a force in a metal strip moving through theinterior of the processing equipment.

Example 41 is the method of examples 39-40, wherein the horizontal wallhas a smaller thickness than a thickness of a vertical wall.

Example 42 is the method of examples 39-41, further comprisingidentifying the section of the outer wall, wherein identifying thesection includes determining a distance of outer wall longitudinallyoffset from one or more adjacent nozzles.

Example 43 is an applied-current magnetic steering apparatus,comprising: a current source for applying a direct current to a metalstrip; a pair of electrodes coupled to the current source and biasedtowards a surface of the metal strip to apply the direct current throughthe metal strip; and a permanent magnet positioned proximate the metalstrip to induce a magnetic field through the metal strip in a directionperpendicular the direction of the direct current passing through themetal strip.

Example 44 is the apparatus of example 43, further comprising: a secondcurrent source for applying a second direct current to the metal strip;a second pair of electrodes coupled to the second current source andbiased towards a second edge of the metal strip to apply the seconddirect current through the metal strip, wherein the pair of electrodesis biased towards a first edge of the metal strip opposite the secondedge of the metal strip; and a second permanent magnet positionedproximate the metal strip to induce a second magnetic field through themetal strip in a direction perpendicular a direction of the seconddirect current passing through the metal strip.

Example 45 is the apparatus of example 43, further comprising: a secondcurrent source for applying a second direct current to the metal strip;and a second pair of electrodes coupled to the second current source andbiased towards a second edge of the metal strip to apply the seconddirect current through the metal strip, wherein the pair of electrodesis biased towards a first edge of the metal strip opposite the secondedge of the metal strip, and wherein the permanent magnet extendslaterally across a width of the metal strip such that the magnetic fieldis induced in a direction perpendicular the direction of the seconddirect current passing through the metal strip.

Example 46 is a method of steering metal, comprising: applying directcurrent along edges of a moving metal strip in a direction parallel adirection of travel of the moving metal strip; and applying at least onemagnetic field along the edges of the moving metal strip such that theat least one applied magnetic field perpendicularly intersects theapplied direct current.

Example 47 is the method of example 46, wherein applying at least onemagnetic field comprises applying a first magnetic field along a firstedge of the moving metal strip and applying a second magnetic fieldalong a second edge of the moving metal strip.

Example 48 is the method of examples 46 or 47, wherein applying thedirect current along the edges of the moving metal strip comprises:completing a first circuit between a first set of electrodes, a firstcurrent source, and a first edge of the moving metal strip; andcompleting a second circuit between a second set of electrodes, a secondcurrent source, and a second edge of the moving metal strip.

What is claimed is:
 1. A method of steering a moving metal strip,comprising: passing a metal strip in a direction of travel along adesired passline of processing equipment, the metal strip adjacent tofirst and second rotors laterally offset from a centerline of the metalstrip and spaced apart from a surface of the metal strip; rotating eachof the first and second rotors about respective first and second axes ofrotation to induce a changing magnetic field at the moving metal strip,the first and second axes of rotation being non-collinear andintersecting a plane perpendicular to the direction of travel of themetal strip; and generating a force in the moving metal strip inresponse to the changing magnetic fields to steer the centerline of themetal strip towards a centerline of the desired passline of theprocessing equipment.
 2. The method of claim 1, further comprising:sensing a position of the metal strip; and controlling an actuatorcoupled to at least one of the first and second rotors based on thesensed position, wherein controlling the actuator includes adjusting atleast one of a horizontal or a vertical position of the at least one ofthe first and second rotors.
 3. The method of claim 1, furthercomprising: accessing a pre-determined parameter of the strip; andcontrolling an actuator coupled to at least one of the first and secondrotors based on the pre-determined parameter, wherein controlling theactuator includes adjusting at least one of a horizontal or a verticalposition of the at least one of the first and second rotors.
 4. Themethod of claim 3, wherein accessing the pre-determined parameter of thestrip includes accessing at least one selected from the group consistingof strip width, strip thickness, and location of the centerline of thedesired passline.
 5. The method of claim 1, further comprising: sensinga position of the metal strip; and controlling a speed of rotation of atleast one of the first and second rotors based on the sensed position.6. The method of claim 1, wherein passing the metal strip includespassing the metal strip at a tension at or below 40 Mpa.
 7. The methodof claim 1, wherein passing the metal strip includes passing the metalstrip at a tension at or below 5 Mpa.
 8. A metal processing system,comprising: processing equipment for receiving a moving metal strip, theprocessing equipment having a desired passline; and a magnetic rotorsteering device positionable proximate the moving metal strip, themagnetic rotor steering device comprising first and second rotors thatrotate about respective first and second axes of rotation, wherein thefirst and second axes of rotation are non-collinear, intersect a planeperpendicular to a direction of travel of the moving metal strip, andare laterally offset from a centerline of the moving metal strip at theplane, and wherein each of the first and second rotors are rotatable toinduce a changing magnetic field at the moving metal strip to generate aforce in the moving metal strip to steer the centerline of the movingmetal strip towards a centerline of the desired passline of theprocessing equipment.
 9. The system of claim 8, wherein the processingequipment is selected from a furnace zone and a cooling zone of acontinuous annealing line.
 10. The system of claim 8, wherein themagnetic rotor steering device is positioned adjacent at least one of anentrance of the processing equipment and an exit of the processingequipment.
 11. The system of claim 8, wherein the magnetic rotorsteering device is positioned between an entrance of the processingequipment and an exit of the processing equipment.
 12. The system ofclaim 8, wherein the processing equipment includes an outer wall havinga recessed section, wherein the magnetic rotor steering device ispositioned at least partially within the recessed section.
 13. Thesystem of claim 8, further comprising: one or more actuators coupled toat least one of the first and second rotors to adjust vertical,horizontal, or vertical and horizontal positioning of the at least oneof the first and second rotors; and a controller coupled to a sensor andthe one or more actuators to adjust the vertical, horizontal, orvertical and horizontal positioning of the at least one of the first andsecond rotors in response to a signal from the sensor.
 14. The system ofclaim 8, wherein at least one of the first and second rotors includesone or more permanent magnets.
 15. The system of claim 8, wherein thefirst rotor is adjacent a first edge of the moving metal strip and thesecond rotor is adjacent a second edge of the moving metal strip,wherein the first edge is located opposite the centerline of the movingmetal strip from the second edge.
 16. The system of claim 8, wherein themoving metal strip is unsupported by a physically contacting support fora section of the processing equipment, and wherein the magnetic rotorsteering device is positioned within the section.